solve the quadratic equation x²+x-2​

Answer:

"Add equations A and B to eliminate [tex]y[/tex]. Add equations A and C to eliminate [tex]y[/tex]".

Step-by-step explanation:

Let be the following system of linear equations:

[tex]4\cdot x + 4\cdot y + z = 24[/tex] (1)

[tex]2\cdot x - 4\cdot y +z = 0[/tex] (2)

[tex]5\cdot x - 4\cdot y - 5\cdot z = 12[/tex] (3)

1) We eliminate [tex]y[/tex] by adding (1) and (2):

[tex](4\cdot x + 2\cdot x) +(4\cdot y - 4\cdot y) + (z + z) = 24 + 0[/tex]

[tex]6\cdot x +2\cdot z = 24[/tex] (4)

2) We eliminate [tex]y[/tex] by adding (1) and (3):

[tex](4\cdot x + 5\cdot x) +(4\cdot y - 4\cdot y) +(z -5\cdot z) = (24 + 12)[/tex]

[tex]9\cdot x -4\cdot z = 36[/tex] (5)

Hence, the correct answer is "Add equations A and B to eliminate [tex]y[/tex]. Add equations A and C to eliminate [tex]y[/tex]".

Answer:

if the terms are approaching zero then it is convergent.

Therefore the stated series is convergent

Step-by-step explanation:

Answer: The first number is 2, the second number is 3 and the third number is -2

Step-by-step explanation:

Let the first number be 'x', the second number be 'y' and the third number be 'z'

The equations according to the question becomes:

⇒ x + y + z = 3              ....(1)

⇒ x - y + z = -3              ....(2)

⇒ x - z = 1 + y              ....(3)

Rearranging equation 3:

⇒ x - y = 1 + z                .....(4)

Putting in equation 2:

⇒ 1 + z + z = -3

⇒ 1 + 2z = -3

⇒ z = -2

Putting this value in equation 4 and equation 1, we get:

⇒ x - y = -1

⇒ x + y = 5

Cancelling 'y' by eliminiation method and equation becomes:

⇒ 2x = 4

⇒ x = 2

Putting value of 'x' and 'z' in equation 1:

⇒ 2 + y - 2 = 3

⇒ y = 3

Hence, the first number is 2, the second number is 3 and the third number is -2

Answer:

if x=0 then they have same value

1 and 2 options are out

for x=-1

g(-1)=1

h(-1)=-1

3 is true

4th

FALSE

for all values except 0, g(x)>h(x)

correct ones are

g(x) > h(x) for x = -1.

For positive values of x, g(x) > h(x).

For negative values of x, g(x) > h(x).

Step-by-step explanation:

Step-by-step explanation:

28:20

Once simplified its 7:5

Answer:

The original graph was shifted 2 units to the left and 5 units down.

Step-by-step explanation:

y = |x|

From this, we go to: y = |x - 2|.

When we want to shift a function f(x) a units to the left, we find f(x - a). So first, the graph was shifted 2 units to the left.

y = |x - 2|.

From this, we go to: y = |x - 2| - 5.

Shifting a function f(x) down b units is the same as finding f(x) - b, so the second transformation was shifting the graph 5 units down.

Answer:

12,500

Step-by-step explanation:

P = R-E

b.e.p : P=0

R=E

140x = 1000000 + 60 x

80x = 1000000

x=12,500

Answer:

∠ BCA = 90°

Step-by-step explanation:

∠ BCA is an angle in the semicircle and equals 90°

width = x

length = 3 + x

perimeter = x + x + ( 3 + x ) + (3+x)

18 = x + x + ( 3 + x ) + (3+x)

x + x + ( 3 + x ) + (3+x) = 18

6 + 4x = 18

4x = 12

x = 3

Answer:

8 suits

Step-by-step explanation:

Divide 30 m by 3 [tex]\frac{3}{4}[/tex] m , or 30 ÷ 3.75 , then

30 ÷ 3.75 = 8

Then 8 suits can be made from 30 m of cloth

Answer:

.0548

Step-by-step explanation:

(2-10)/5= -1.6

go to a ztable and get .0548

Answer:

Step-by-step explanation:

Part A.....let P be the number of people that will show up.....so....

The total amount of broccoli needed (in ounces)  =    8P  ounces

Part B

32  =  8P       divide both sides by 8

4 = P            so.....4 people can be fed.....!!!

Step-by-step explanation:

Answer:

11 half years

Step-by-step explanation:

The formula for compound interest is

A = P(1+r/n)^(nt), with r representing the interest rate, n being the number of times interest is applied over the time period, and t being the amount of time periods.

If we make the time period a half year (so interest is compounded once per time period), n=2. Then, our interest rate is 7%, or 0.07 (to convert from percent to decimal, simply divide by 100). Our starting amount is 500, and we want it to double, making it 1000. Our formula is thus

1000 = 500 (1+0.07)^(t)

divide both sides by 500

2 = (1+0.07)^(t)

2 = (1.07)^(t)

Using logarithms, we can say that

[tex]log_{1.07} 2 = t[/tex]

and using a calculator, we get

10.24 = t

Since interest is only compounded once per time period, though, we have to round up to make sure it doubles, so t = 11

Answer:

[tex]Sales = 86.749[/tex]

Step-by-step explanation:

Given

[tex]Sales = 0.845*(competitors) + 5.79*(population) + 13.889[/tex]

[tex]Competitors = 4[/tex]

[tex]Population = 12000[/tex]

See comment for complete question

Required

The sales

We have:

[tex]Sales = 0.845*(competitors) + 5.79*(population) + 13.889[/tex]

Substitute values for competitors and population

[tex]Sales = 0.845*4 + 5.79*12 + 13.889[/tex]

[tex]Sales = 3.38 + 69.48 + 13.889[/tex]

[tex]Sales = 86.749[/tex]

Answer:

90

Step-by-step explanation:

=> x + y = 12

=> x² + y² + 2xy = 144

=> x² + y² + 2 * 27 = 144

=> x² + y² = 144 - 54

=> x² + y² = 90

Answer:

the larger number is 69

the smaller number is 16

Step-by-step explanation:

x is the smaller number

y is the larger number

x + y = 85

y - 4x = 5

y = 5 + 4x

x + 5 + 4x = 85

5x = 80

x = 16

y = 69

Answer:

x = -2; y = 1

Step-by-step explanation:

See picture below.

We are told matrices B is the inverse of matrix A.

The product of a matrix and its inverse is the identity matrix.

Answer:

30

Step-by-step explanation:

The given is right triangle with angle measure 90-60 and 30 degrees as we can see on the image.

Answer:

b) 6.68%

Step-by-step explanation:

Normal Probability Distribution

Problems of normal distributions can be solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

The mean score on the scale is 50. The distribution has a standard deviation of 10.

This means that [tex]\mu = 50, \sigma = 10[/tex]

Matthew scores a 65. What percentage of people could be expected to score the same as Matthew or higher on this scale?

The proportion is 1 subtracted by the p-value of Z when X = 65. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{65 - 50}{10}[/tex]

[tex]Z = 1.5[/tex]

[tex]Z = 1.5[/tex] has a p-value of 0.9332.

1 - 0.9332 = 0.0668

0.0668*100% = 6.68%

So the correct answer is given by option b.

Given that exp(2x) is a solution, we assume another solution of the form

y(x) = v(x) exp(2x) = v exp(2x)

with derivatives

y' = v' exp(2x) + 2v exp(2x)

y'' = v'' exp(2x) + 4v' exp(2x) + 4v exp(2x)

Substitute these into the equation:

(2x + 5) (v'' exp(2x) + 4v' exp(2x) + 4v exp(2x)) - 4 (x + 3) (v' exp(2x) + 2v exp(2x)) + 4v exp(2x) = 0

Each term contains a factor of exp(2x) that can be divided out:

(2x + 5) (v'' + 4v' + 4v) - 4 (x + 3) (v' + 2v) + 4v = 0

Expanding and simplifying eliminates the v term:

(2x + 5) v'' + (4x + 8) v' = 0

Substitute w(x) = v'(x) to reduce the order of the equation, and you're left with a linear ODE:

(2x + 5) w' + (4x + 8) w = 0

w' + (4x + 8)/(2x + 5) w = 0

I'll use the integrating factor method. The IF is

µ(x) = exp( ∫ (4x + 8)/(2x + 5) dx ) = exp(2x - log|2x + 5|) = exp(2x)/(2x + 5)

Multiply through the ODE in w by µ :

µw' + µ (4x + 8)/(2x + 5) w = 0

The left side is the derivative of a product:

[µw]' = 0

Integrate both sides:

∫ [µw]' dx = ∫ 0 dx

µw = C

Replace w with v', then integrate to solve for v :

exp(2x)/(2x + 5) v' = C

v' = C (2x + 5) exp(-2x)

∫ v' dx = ∫ C (2x + 5) exp(-2x) dx

v = C₁ (x + 3) exp(-2x) + C₂

Replace v with y exp(-2x) and solve for y :

y exp(-2x) = C₁ (x + 3) exp(-2x) + C₂

y = C₁ (x + 3) + C₂ exp(2x)

It follows that the second fundamental solution is y = x + 3. (The exp(2x) here is already accounted for as the first solution.)

Answer: third from the top

Step-by-step explanation:

The correct answer is third from the top.

Arranging numbers in ascending order:

15 17 17 17 18 18 18 19 19 19 21 21 22 23 24

Let's count how many times each number occurs in this series of numbers.

row of numbers

15 +

16 not

17 + + +

18 + + +

19 + + +

20 not

21 + +

22 +

23 +

24 +

25 not

9514 1404 393

Answer:

Step-by-step explanation:

The graph shows the function value is zero for x=5 and x=7. These are the elements of the solution set.

  x ∈ {5, 7}

__

The graph is below the x-axis between these points, so that is the region where f(x) < 0

  5 < x < 7 . . . . . for f(x) < 0

In interval notation: (5, 7).

Answer:

obtuse cant be a right angle

Step-by-step explanation:

in order to be  obtuse you  have to be more than 90 dagrees

Answer:

Part 1)

225 feet.

Part 2)

7 seconds.

Step-by-step explanation:

The height h(t) of the ball above the ground after t seconds is modeled by the function:

[tex]h(t)=-16t^2+104t+56[/tex]

Part 1)

We want to determine the maximum height of the ball.

Notice that the function is a quadratic with a negative leading coefficient, so its maximum will be at its vertex point.

The vertex of a parabola is given by:

[tex]\displaystyle \text{Vertex} = \left(-\frac{b}{2a}, f\left(-\frac{b}{2a}\right)\right)[/tex]

In this case, a = -16, b = 104, and c = 56.

Find the x- (or rather t-) coordinate of the vertex. So:

[tex]\displaystyle t=-\frac{(104)}{2(-16)}=\frac{104}{32}=\frac{13}{4}=3.25\text{ seconds}[/tex]

In other words, the ball reaches its maximum height after 3.25 seconds.

To find the maximum height, substitute this value back into the function. Hence:

[tex]\displaystyle h(3.25)=-16(3.25)^2+104(3.25)+56=225\text{ feet}[/tex]

The maximum height of the ball is 225 feet in the air.

Part 2)

We want to find the amount of time it took for the ball to hit the ground.

When the ball hit the ground, its height above the ground is zero. Therefore, we can set h(t) to 0 and solve for t:

[tex]0=-16t^2+104t+56[/tex]

We can simplify a bit. Divide both sides by -8:

[tex]0=2t^2-13t-7[/tex]

We can factor. Find two numbers that multiply to 2(-7) = -14 and add to -13.

-14 and 1 works! Therefore, split the second term into -14 and 1:

[tex]\displaystyle 0=2t^2-14t+t-7[/tex]

Factor out a 2t from the first two terms and group the last two terms:

[tex]0=2t(t-7)+(t-7)[/tex]

Factor by grouping:

[tex]0=(2t+1)(t-7)[/tex]

Zero Product Property:

[tex]2t+1=0\text{ or } t-7=0[/tex]

Solve for each case:

[tex]\displaystyle t=-0.5\text{ or } t=7[/tex]

Since time cannot be negative, we can ignore the first case.

Therefore, it takes seven seconds for the ball to hit the ground.

Answer:

Peter is a-8 in 9 years, (a-8)+ 9+ a+ 9= 76

Answer:

P = 25

A = 33

Step-by-step explanation:

P + 8 = A

P + 9 + A + 9 = 76

P + A = 58

~~~~~~~~~~~~~~

P = 58 - A

P = 58 - P - 8

2 P = 50

P = 25

A = 33

I believe this is your question:

A.) find an angle between 0 degrees and 360 degrees that is coterminal with 570 degrees.

Answer:

210 degrees

Explanation:

Coterminal angles begin on the same initial side and end or terminate on the same side as an angle. Example 45 degrees and 405 degrees are coterminal angles because they both begin and end on the same side.

To find an angle between 0 and 360 that is coterminal with 570 degrees, w simply subtract 360 degrees from 570, hence:

570-360=210 degrees

570 degrees is coterminal with 210 degrees

Answer:

BH/2

Step-by-step explanation:

For the area of the triangle, (BH)/2. B=base and H=height

y = -7(-13)

=> y = -7 × (-13)

= y = 91

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