mr.brown can type 80 words in two minutes. how many words can he type in 40 minutes?

Answer:

11 terms.

Step-by-step explanation:

We are given the arithmetic sequence:

17, 13, 9, ...

And we want to find the number of terms required such that the sum is -33.

Recall that the sum of an arithmetic series is given by:

[tex]\displaystyle S = \frac{k}{2}\left( a + x_k\right)[/tex]

Where k is the number of terms, a is the first term, and x_k is the last term.

The desired sum is -33. The first term is 17 as well. Thus:

[tex]\displaystyle (-33) = \frac{k}{2} \left( (17) +x_k\right)[/tex]

Simplify:

[tex]-66 = k(17 + x_k)[/tex]

We can write a direct formula to find the last term x_k. The direct formula of an arithmetic sequence has the form:

[tex]x_ n = a + d(n-1)[/tex]

Where a is the initial term and d is the common difference.

The initial term is 17 and the common difference is -4. Hence:

[tex]\displaystyle x_n = 17 - 4(n-1)[/tex]

Then the last term is given by:

[tex]x_k = 17 - 4(k-1)[/tex]

Substitute:

[tex]\displaystyle -66 = k\left( 17 + \left( 17 - 4(k-1)\right)\right)[/tex]

Solve for k:

[tex]\displaystyle \begin{aligned} -66 &= k(17 + (17 - 4k + 4)) \\ -66 &= k(38 -4k) \\ -66 &= -4k^2 + 38k \\ 4k^2 -38k -66 &= 0 \\ 2k^2 - 19k -33 &= 0 \\ (k-11)(2k+3) &= 0 \\ k-11&= 0 \text{ or } 2k+3 = 0 \\ \\ k &= 11 \text{ or } k = -\frac{3}{2}\end{aligned}[/tex]

Since we cannot have a negative amount of terms, we can ignore the second solution.

Therefore, the given sequence must have 11 terms such that it sums to -33.

Answer:

Here is 2 methods

Step-by-step explanation:

1) we use excel to find n=11 for lasy students

2) mathematical method

[tex]u_1=17\\u_2=13=17+(2-1)*(-4)\\u_3=9=17+(3-1)*(-4)\\\\\\\boxed{u_n=17+(n-1)*(-4)}\\\\\\\displaystyle s_n=\sum_{i=1}^nu_i\\=\sum_{i=1}^n(17+(i-1)*(-4))\\\\\\=(\sum_{i=1}^n 17) + (-4)*\sum_{i=1}^n (i) +4*\sum_{i=1}^n (1)\\\\\\=17*n+4*n-4*\frac{n*(n+1)}{2} \\\\\\=21n-2n^2-2n\\\\\\=-2n^2+19n\\\\=-33\\\\\\\Longrightarrow\ 2n^2-19n-33=0[/tex]

[tex]\Delta=19^2+4*2*33=625=25^2\\\\n=\dfrac{19-25}{4} =-1.5\ (excluded)\ or\ n=\dfrac{19+25}{4}=11\\\\[/tex]

The triangle is missing and so i have attached it.

Answer:

x = 93°

Step-by-step explanation:

From the triangle attached, we can say that;

<SQP + <SQR = 180°

This is because sum of angles on a straight line equals 180°.

Secondly, we know that sum of angles in a triangle also equals 180°.

Thus;

<SQR + <QSR + <SRQ = 180

From the attached triangle, we see that;

<QSR = 35°

<SRQ = 58°

Thus;

<SQR + 35° + 58° = 180°

<SQR + 93° = 180°

<SQR = 180° - 93°

<SQR = 87°

From earlier on, we saw that;

<SQP + <SQR = 180°

Plugging in <SQR = 87°, we have;

<SQP + 87° = 180°

<SQP = 180° - 87°

<SQP = 93°

We are told in the question that <SQP is denoted by x.

Thus;

x = 93°

Answer:

The value of x is answer D: 93

9514 1404 393

Answer:

  -4/3

Step-by-step explanation:

Quadratic ax² +bx +c can be written in factored form as ...

  a(x -p)(x -q)

for zeros p and q. The expanded form of this is ...

  ax² -a(p+q)x +apq

Then the ratio of the constant term to the leading coefficient is ...

  c/a = (apq)/a = pq . . . . the product of the zeros

For your quadratic, the ratio c/a is -4/3, the product of the zeros.

_____

Additional comment

You will notice that the sum of zeros is ...

  -b/a = -(-a(p+q))/a = p+q

Answer:

[tex] \green{ \boxed{ \bf \: product \: of \: the \: zeros \: = - \frac{4}{3} }}[/tex]

Step-by-step explanation:

We know that,

[tex] \sf \: if \: \alpha \: and \: \beta \: \: are \: the \: zeroes \: of \: the \: \\ \sf \: polynomial \: \: \: \pink{a {x}^{2} + bx + c }\: \: \: \: then \\ \\ \small{ \sf \: product \: of \: zeroes \: \: \: \alpha \beta = \frac{constant \: term}{coefficient \: of \: {x}^{2} } } \\ \\ \sf \implies \: \pink{ \boxed{\alpha \beta = \frac{c}{a} }}[/tex]

Given that, the polynomial is :

[tex] \bf \: 3 {x}^{2} - 2x - 4[/tex]

so,

[tex] \sf \: so \: product \: of \: zeroes \: \: = \frac{ - 4}{3} = - \frac{4}{3} [/tex]

Answer:

(2,1)

Step-by-step explanation:

2x - 2y = 2

5x + 2y = 12

again just add them in this case

7x = 14

x = 2

4 - 2y = 2

-2y = -2

y = 1

Answer:

56000 ft

Step-by-step explanation:

4000 steps a day.

7 days in a week.

2 ft per step

so, we calculate how many steps in a week

4000 × 7 = 28000

and then we calculate the distance by saying each of these steps is 2 ft

so,

28000 × 2 = 56000 ft

as a little extra thought :

there are 5280 ft in a mile.

so, the person walks

56000 / 5280 miles = 10.61 miles

in a week.

Answer:

x=-2

Step-by-step explanation:

Answer:

Since a = 2, the equation for the directrix line will be y = −2.

Step-by-step explanation:

Answer:

12

Step-by-step explanation:

We can say that two polygons are similar to each other if both of the polygons have the same shape and their corresponding sides are in the same proportion, hence the ratio of their corresponding sides are equal to each other.

As we can see from the problem since both of the polygons are similar, hence the ratio of their corresponding sides are in the same proportion, therefore let x represent the missing length, hence:

[tex]\frac{x}{15} =\frac{32}{40} =\frac{32}{40} \\\\\frac{x}{15} =\frac{32}{40} \\\\x=\frac{32*15}{40} \\\\x=12[/tex]

Answer:

Its AA similaroty theorem

Answer:

13.25×5+13, cost per day with a helmet.

Step-by-step explanation:

Numerical Expressions • Practice

Answer:

13.25×5+13, Per day without a helmet

Step-by-step explanation:

- X + 3Y = 2  (*)

⇔X = 2 - 3Y  (1)

- Y = 2X + 3   (2)

(1),(2)⇒ Y = 2(2 - 3Y) +3

       ⇔ Y = 4 - 6Y + 3

       ⇔ Y = 1  (**)

(*),(**)⇒ X + 3×1 =2

       ⇔ X = -1

Step-by-step explanation:

between -5 and -62

-7,-10,-60...so..on

between -1/7 and 1/8

Multiply any number by number with both the numbers but it should be multiplied by both the numbers:

for example:

-1/7×3/3= -3/21 ; 1/8×3/3= 3/24

So,

-2/21,2/24,1/24

hope it helps

Answer:

Step-by-step explanation:

The diagonal of this rectangular box serves as the hypotenuse of the 2 right triangles that exist within this rectangle. The length is one leg, the hypotenuse is...well, the hypotenuse, so we need to use Pythagorean's Theorem to find the missing leg.

[tex]10^2=8^2+x^2[/tex] and

[tex]100-64=x^2[/tex] and

[tex]x^2=36[/tex] so

x = 6. The width is 6.

Answer:

vertical

Step-by-step explanation:

The line x = -5 includes all points where the value of x is -5, regardless of the value of y. This can be graphed as a vertical line going through (-5, 0), as the line represents the only place where x is the value -5.

Answer:

[tex]\frac{10}{21}[/tex]

Step-by-step explanation:

The LCM of 14, 21 and 6 is 42

We require to change the fractions to fractions with a denominator of 42

[tex]\frac{3(3)}{14(3)}[/tex] + [tex]\frac{2(2)}{21(2)}[/tex] + [tex]\frac{1(7)}{6(7)}[/tex]

= [tex]\frac{9}{42}[/tex] + [tex]\frac{4}{42}[/tex] + [tex]\frac{7}{42}[/tex] ← add the numerators, leaving the denominator

= [tex]\frac{9+4+7}{42}[/tex]

= [tex]\frac{20}{42}[/tex] ← divide both values by 2

= [tex]\frac{10}{21}[/tex] ← in simplest form

Answer:

The answer is Angle 4 and Angle 3.

Answer:

It's answer is angle 4 and angle 3

Answer:

4/9

Step-by-step explanation:

negative exponent means 1/...

so, this is

(32/243)^(4/10) = (32/243)^(2/5)

that means to the power of 2 and then pulling the 5th root.

so, let's pull the 5th root first, and then we square

(32/243)^(2/5) = (2⁵/3⁵)^(2/5) = (2/3)^2 = 4/9

Answer:

20

Step-by-step explanation:

we know,

n(aUb)=n(a)+n(b)-n(a∩b)

so,

80=40+60-n(a∩b)

or, 80-(40+60)=-n(a∩b)

or, -n(a∩b)=80-100

or, -n(a∩b)=-20

or, n(a∩b)=20

Answer:

60+14.35=88.27

Step-by-step explanation:

5x12 for the rectangle on the right, then for the circle, using the formula A=πr², I get 28.27, which you divide by 2 because you only need half of the circle, and you get 88.27. I calculated the radius by subtracting 12-6 and then dividing that in half because the radius is half of the distance to the other end of the circle. Then you get the radius of 3, then plug it into the formula to get π(3)², which is just 3.14(9), and you get 28.27.

Answer:

P = 37.42478 A = 88.27

Answer:

h = 41.52 feet

Step-by-step explanation:

The volume is π•radius²•height:

π•4²•h = 2087

16πh = 2087

h = 2087/16π

h ≈ 41.52 feet

9514 1404 393

Answer:

  9.23%

Step-by-step explanation:

The account balance for simple interest is given by ...

  A = P(1 +rt) . . . . . principal P invested for t years at rate r

  554 = 379(1 +r·5)

  554 = 379 + 1895r . . . . eliminate parentheses

  175 = 1895r . . . . . . . . . subtract 379

  r = 175/1895 ≈ 0.092348 ≈ 9.23%

Jennifer's account had an interest rate of about 9.23%.

Answer:

Circumference is 43.982 cm

Step-by-step explanation:

[tex]circumference = 2\pi r \\ = (2 \times 3.14 \times 7) \\ = 43.982 \: cm[/tex]

[tex]{ \underline{ \tt{ ‡†‡ \: \: trent008}}}[/tex]

Answer:

Original number = 38

Step-by-step explanation:

10*x + y

x   = y - 5

10y + x = 2 (10x + y) +  7

10y + y - 5 = 2(10(y - 5) + y) + 7

11y - 5 = 2(10y - 50 + y ) + 7

11y - 5 = 2(11y - 50) + 7

11y - 5 = 22y - 100 + 7

11y - 5 = 22y - 93

11y + 88 = 22y

88 = 11y

y = 8

x = y - 5

x = 8 - 5

x = 3

So the original number is 38. Does that work?

3 is 5 less than 8.

83 = 2*38 + 7

83 = 76 + 7

83 = 83.         Yes it works.

Answer:

768

Step-by-step explanation:

(8×8×10)+(8×8×6/3)

= 640+128

= 768

Answered by GAUTHMATH

Answer:

The sales tax rate is 5%.

Step-by-step explanation:

To determine the sales tax rate if you already know the amount of tax being added to the purchase price, divide the amount of tax by the purchase price. In this example, divide $1.29 (amount of tax being added) by $25.79 (purchase price). When you do that, you will see that the answer is 0.0500, or 5%.

Answer:

70.7 deg, 19.3 deg

Step-by-step explanation:

The sum of the measures of complementary angles is 90 deg.

One angle measures x.

The other angles measures 51.4 deg less than x, or x - 51.4.

The sum of their measures equals 90.

x + x - 51.4 = 90

2x - 51.4 = 90

2x = 141.4

x = 70.7

x - 51.4 = 70.7 - 51.4 = 19.3

Answer: 70.7 deg, 19.3 deg

Answer:

75... but I don't see it down there

Step-by-step explanation:

equation:

0.5(120) = 0.8(x)

60 = 0.8x

60/8 = 0.1x

7.5 = 0.1x

x = 75

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-Chetan K