Help please!!! I’m having trouble

A 13ft board is to be cut into three pieces, two equal length ones and the third 9in shorter than each of the other two. If cutt

vaieri [72.5K]

Answer:

The pieces are 55 inches, 55 inches and 46 inches long

Step-by-step explanation:

A 13ft board is to be cut into three pieces consisting of two equal length ones. The third one is 9in shorter than each of the other two.

Let us first convert the length of the board to inches:

1 ft = 12 inches

13 ft = 12 * 13 = 156 inches

Let the length of each of the other two pieces be x.

Therefore, the length of the third piece is (x - 9)

Therefore, the sum of the lengths of the three pieces is equal to 156 inches. This means that:

x + x + (x - 9) = 156

x + x + x - 9 = 156

=> 3x = 156 + 9

3x = 165

x = 165 / 3 = 55 inches

Each of the first two pieces are 55 inches long.

The length of the third piece will be:

55 - 9 = 46 inches

The pieces are 55 inches, 55 inches and 46 inches long.

4 0

3 years ago

-7x-3x+2=-8x-2 can you please show your work how

iVinArrow [24]

Answer:

x = 2

Step-by-step explanation:

Given

- 7x - 3x + 2 = - 8x - 2 ← simplify left side

- 10x + 2 = - 8x - 2 ( add 8x to both sides )

- 2x + 2 = - 2 ( subtract 2 from both sides )

- 2x = - 4 ( divide both sides by - 2 )

x = 2

8 0

3 years ago

travis drove 129 miles in 3 hours.he drove at a constant speed.how many miles did he drive in 1 hour?

Dennis_Churaev [7]

Do one hundred and twenty nine divided by three and you will get your answer

5 0

3 years ago

Read 2 more answers

Please explain I don’t I understand help

djyliett [7]

Answer:

Step-by-step explanation:

f (x) = (5(-4)) + a) (3/5 + 4) ( 6 + b)

f (x) = (-20 + a) (6 2/5) (6 + b)

f ( -20 ) = -20 + -20 (a) (6 2/5) (6 + b)

f ( -20 - 6 2/5 ) = (a) (6 2/5 -6 2/5) (6 + b)

f (-26 2/5 - 6 ) = (a) (6-6 +b)

f (-32 2/5-6) = (a) (b)

4 0

2 years ago

2. Carl needs 15 hours longer than Jennifer to paint a room. If they work together, they can complete the job in 4 hours. Explai

nasty-shy [4]

Answer:

Jennifer would complete the job on her own in 5 hours.

Step-by-step explanation:

Solving a quadratic equation:

Given a second order polynomial expressed by the following equation:

$ax^{2} + bx + c, a\neq0$ .

This polynomial has roots $x_{1}, x_{2}$ such that $ax^{2} + bx + c = a(x - x_{1})*(x - x_{2})$ , given by the following formulas:

$x_{1} = \frac{-b + \sqrt{\Delta}}{2*a}$

$x_{2} = \frac{-b - \sqrt{\Delta}}{2*a}$

$\Delta = b^{2} - 4ac$

Rates

The together rate is the sum of their separates rate.

We have that:

Jennifer takes x hours to complete the job on her own, so her rate is 1/x.

Carl needs 15 hours longer than Jennifer, that is, 15 + x hours, so his rate is 1/(15+x).

The together rate is 1/4. So

$\frac{1}{4} = \frac{1}{x} + \frac{1}{15+x}$

$\frac{1}{4} = \frac{15 + x + x}{x(15+x)}$

$\frac{1}{4} = \frac{15 + 2x}{x(15+x)}$

Applying cross multiplication.

$x^2 + 15x = 4(15 + 2x)$

$x^2 + 15x = 60 + 8x$

$x^2 + 7x - 60 = 0$

Quadratic equation with $a = 1, b = 7, c = -60$ . So

$\Delta = 7^{2} - 4*1*60 = 289$

$x_{1} = \frac{-7 + \sqrt{289}}{2} = 5$

$x_{2} = \frac{-7 - \sqrt{289}}{2} = -12$

Since the time to complete the job has to be a positive value.

Jennifer would complete the job on her own in 5 hours.

4 0

2 years ago