What should be done so that the expression will have a value of 20?

8 + 4 - 22 x 3

Answer:

23.4 km

Step-by-step explanation:

We can use a ratio to solve

13 km         x km

--------   = ---------------

5 hours         9 hours

Using cross products

13*9 = 5x

117 = 5x

Divide each side by 5

117/5 = 5x/5

23.4 =x

Answer:

It travel 23.4 km in 9 hours.

Step-by-step explanation:

Given :-

A sea turtle can swim 13 km in 5 hours at this rate speed .

To find :-

How far can it travel in 9 hours.

Solution :-

Sea turtle swim 13 km in 5 hours Then find the how far it can travel in 9 hours.

Let us assume that In 9 hours turtle swim x km.

Now, We solve by using ratio for x.

In 5 hours it swim = 13 km

And, In 9 hours it swim = x km

Calculate for x

5 hours = 13 km

9 hours = x km

Use cross multiplication method , we get

5 × x = 9 × 13

5x = 117

Divide both side by 5

5x / 5 = 117 / 5

x = 23.4

Hence, It can travel 23.4 km in 9 hours.

Answer:

Step-by-step explanation:

Eq. 1 )   −5x−3y−9=0

Eq. 2)   4x−18y−54=0

there are two routes to solve this,   Substitution or  elimination,  I'll go for the 2nd one because I can see that the y values are a multiple of each other :)

    6 *( −5x−3y−9=0 )

Eq. 3) -30x -18y =54

subtract Eq. 2 from Eq. 3  :)

-30x -18y =54

-( 4x−18y=54)

-34x = 0

so according to the equations then x =0 but,  that's not really a full answer, so now we should go back and try the other method, substitution,

then:

-5x = 9 +3y

x = - 9/5 + (-3/5)y

now plug that into Eq. 2

4( - 9/5 + (-3/5)y ) - 18y = 54

-36/5 + (-12/5)y -18y = 54

(-12/5)y - (90/5)y = 54+36/5

-(102/5)*y =270/5+36/5

-(102/5)y = 306/5

y = (-5/102)*(306/5)

y = -306/102

y = -3

then plug in for either equation

-5x-3( -3) = 9

-5x + 9 = 9

-5x = 0

x = 0

now we have the full answer

check it by plugging in both x and y into the 2nd equation

4(0) - 18(-3) = 54

54= 54

this seems good  

Answer:

Step-by-step explanation:

I'm assuming you're looking for the age of the mammal hide, since there's no question here, but there's also nothing else to solve for. Remember a few things before we move on. First, if we are not told the initial amount with which we start, we have to assume that it's 100%. Second, remember that natural log and e are inverses of each other so they eliminate each other in application. Now to set up the problem. It looks like this:

[tex]71=100e^{-.0001t}[/tex] and begin by dividing both sides by 100 to get

[tex].71=e^{-.0001t}[/tex] and take the natural log of both sides. The other important thing to remember about the rules for logs and natural logs is that when you take the natural log of something, you are "allowed" to move the exponent down out front, which is why we do this. We cannot currently solve for t when it's stuck up there where it is right now. Taking the natural log allows us to bring that exponent down AND eliminate both the natural log and the e at the same time:

ln(.71) = -.0001t and we divide to solve for t:

[tex]\frac{ln(.71)}{-.0001}=t[/tex] and

[tex]\frac{-.3424903089}{-.0001}=t[/tex] so

t = 3424.9 years, or rounded, 3425 years.

Answer:

d=3

Step-by-step explanation:

13d=39

d=39/13

d=3

Hello!

6d + 7d = 39 <=>

<=> 13d = 39 <=>

<=> d = 39 : 13 <=>

<=> d = 3 => 6 × 3 + 7 × 3 = 39

Good luck! :)

Answer:

Answer:

(40,30)

Step-by-step explanation:

This is when the prices are the same so they cross on the graph.

Answer:

C

Step-by-step explanation:

We want to find the ordered pair that estimates the time and cost at which the two stores charge the same amount

If the graph shows the two stores times and amount charged then wherever the two lines intersect is where the time and amount charged is the same

The two lines intersect at (40,30)

Hence the answer is C

Answer:

6x - 15

Step-by-step explanation:

f(x) = 2x + 3 and g(x) = 3x - 9.

[tex]f(g(x))=2(3x-9)+3\\f(g(x))=6x-18+3\\f(g(x))=6x-15[/tex]

Answer:

-37

Step-by-step explanation:

-155-20-14-133-73=-395

190+170=360

-395+360=-37

Answer:

Step-by-step explanation:

1) 2/9 = 185/x

  2x = 1665

x = 832.5 or 8.325 meters

2) unit rate is the cost of one unit

i.e a dozen eggs cost $1.20 that

would be 10 cents each

3) 300 tissues for $3.75 vs. 250 for $2.99

one is 1.24 cents per tissue

the other 1.19 ... the 250 package is a better buy

Answer:

152-88 = 64

Step-by-step explanation:

Solution to the question:

Number of blocks stacked: 30

Height of tower: 64 inches

Height of each block: ?

To find the height of each block, we divide the total height of the tower with the number of blocks stacked

Therefore,

Height of each block: 64/30 = 2.13 inches

So, the height of each block is 2.13 inches.

Answer:

The value of x is 8 .

Step-by-step explanation:

It is known that EF = x cm , GH = (x + 6) cm , RS = 16 cm and NP = 28 cm . Knowing that EF ,GH , RS , and NP are, in that order, proportional segments, determine the value of x .

As EF, GH, RS and NP are in proportion

So,

EF : GH = RS : NP

[tex]\frac{x}{x+6}=\frac{16}{28}\\\\7 x = 4 (x + 6)\\\\7 x = 4 x + 24 \\\\3 x = 24 \\\\x = 8[/tex]

Answer:

9<x<23

Step-by-step explanation:

I'm not sure if this is what it wants, but theres this theorem that says a side needs to be less than the other two combined.

x+7>16

x+16>7

16+7>x

=>

x>9

x>-9

x<23

=>

9<x<23

Answer:

im bad at math but i think its 120

Answer: f(3)=-7

Step-by-step explanation:

To evaluate f(3), we want to plug in x=3 into f(x)=-4x+5.

f(3)=-4(3)+5       [multiply]

f(3)=-12+5          [add]

f(3)=-7

Now, we know that f(3)=-7.

Answer:

x > 23/5

Step-by-step explanation:

2x+ 3(x+2)>17

2x + 3x + 6 >17

5x >23

x > 23/5

Answer:

-2.179

Step-by-step explanation:

Given :

Degree of freedom, df = 12

Area to the left = 0.025

The value of T can be obtained using either a t distribution table or a T value calculator :

t0.025, 12 (to the left) = t(1-0.025), 12 = t0.975,12 = - 2.1788

Therefor le, t value with 12 degree of freedom, with area to the left being 0.025 is - 2.179

Answer:

6.270

Step-by-step explanation:

3 is below 5 so you just turn it into a 0. If it was 5 or above you would just add a number to the 7.

Answer:

63/70 = 9 : 10

Step-by-step explanation:

Given ratio:

9/10

a 70/63

= 10/9

= 10 : 9

b 19/70

= 19:70

c 19/20

= 19 : 20

d 63/70

= 9/10

= 9 : 10

The equivalent ratio to 9/10 = 63/70

= 9 : 10

Answer: the income is 369$

Step-by-step explanation:

Answer:

9, 10, 11, 12

Step-by-step explanation:

Let the consecutive numbers be:

x, x+1, x+2, x+3

Greatest of the numbers will be: x + 3

x+x+1+x+2+x+3 = 3(x+3) + 2

4x + 6 = 3(x+4) + 2

4x + 6 = 3x + 12 + 2

4x + 6 = 3x + 14

Collect like terms

4x - 3x = 14 - 6

x = 8

x +1 = 8+ 1 = 9

x + 2 = 8 + 2 = 10

x + 3 = 8 + 3 = 11

x + 4 = 8 + 4 = 12

Answer:

She should have included an exponent of 2 on the 3

Step-by-step explanation:

The factor tree can be presented as follows;

                [tex]{}[/tex]                                90

[tex]{}[/tex]                                                  ↓

[tex]{}[/tex]                                     9          ↔            10

[tex]{}[/tex]                                     ↓                           ↓

[tex]{}[/tex]                                3  ↔  3                  2  ↔  5

Therefore, the prime factorization of 90 is equal to 90 = 3 × 3 × 2 × 5

She should have wrote, 90 = 3² × 2 × 5

Therefore, the error is that she should have included an exponent of 2 on the 3.

Answer:

B

✔ She should have included an exponent of 2 on the 3.

Step-by-step explanation:

E2021

Answer:

30 seconds

Step-by-step explanation:

→ Work out how many floors it's going to travel

15 - 3 = 12 floors

→ Work out how many meters 12 floors is

12 × 5 = 60 meters

→ Work out how long that will take

60 ÷ 2 = 30 seconds

Answer:

gradient = slope = [tex]\frac{y_{2} -y_{1} }{x_{2} -x_{1} }[/tex] = [tex]\frac{rise}{run}[/tex]

Slope intercept Form equation : y = mx + b

m = slope or gradient

b = y - intercept ( where the line crosses the y = axis)

x and y = are place holders for a coordinate pair that makes the equation true

c) y = -6x + 8

The -6 is the m. It's the slope or gradient.

the + 8  is the b. It's the y- intercept.

d) y = 4

This is a horizontal line. It intercepts the y-axis at 4.

That means the 4 is the y-intercept.

There is no x. That means the slope is 0. The line rises 0 as it runs left to right.

e) y -4x= 0  

equation needs to be is standard form y = mx + b.

add 4x to both sides in order to isolate the y variable.

y = 4x + 0.

The slope or gradient is 4. The y - intercept is 0. The line crosses through the origin.

f) y -x = -8

Add x to both sides.

y = x - 8

There is one x.  That means the gradient is 1. The y-intercept is the -8

g) y + 3x = 7

Subtract 3x from both sides.

y = -3x + 7

-3 = gradient. 7 = y-intercept.

h) y + [tex]\frac{1}{2}[/tex]x = -4

Subtract [tex]\frac{1}{2}[/tex]x from each side.

y = -[tex]\frac{1}{2}[/tex]x - 4

One last thing. If you are presented with an equation without a y, the gradient is  'undefined'.

example : x = 4

This a vertical line passing through 4 on the x-axis. There is no 'b' because its not crossing the y-axis.

Why is it 'undefined' ?

As the line rises it, it does not 'run' left or right. [tex]\frac{rise}{0}[/tex] . Zero can never, ever be in the denominator. Denominators can't be zero. That is why we say it's 'undefined'.

Hope this helps.

Answer:

Domain = ( -∞ , ∞ )

Range = ( ∞ , ∞ )

Step-by-step explanation:

A function is given to us and we need to find the domain and range of the given function .

The function :-

[tex]\rm \implies y = \dfrac{1}{4}x - 6 [/tex]

Definitions :-

In this case, there is no real number that makes the expression undefined. Therefore the domain will be :-

Domain :-

[tex]\rm Domain = ( -\infty , \infty ) [/tex]

or

[tex]\rm Domain = \{ x | x \in \mathbb{R} \}[/tex]

Range :-

[tex]\rm Range = ( -\infty , \infty ) [/tex]

or

[tex]\rm Range = \{ y | y \in \mathbb{R}\} [/tex]

Answer:

Create a table or a graph of the function. The domain represents all input values and the range represents all output values. The domain and range contain all real numbers.

Step-by-step explanation:

Answer:

C; 4

Step-by-step explanation:

Mathematically, when two lines are perpendicular, the product of their slopes equal -1

in that case, we have it that;

m1 * m2 = -1

where m1 is the slope of the first line and m2 is the slope of the second line

Hence,

m2* -1/4 = -1

-m2/4 = -1

-m2 = -4

m2 = 4

Answer:

-4/3

Step-by-step explanation:

-3 x (-2/3)²

= -3 x (4/9)

= -4/3

Answer:

then why are you asking?

Step-by-step explanation:

okay