Anonymous
Anonymous asked in Science & MathematicsMathematics · 6 days ago

# "The area of a rectangle is (x2-13x-30). If the width is (x+2),find the length." Can someone go through this step by step?

Relevance
• sepia
Lv 7
4 days ago

The area of a rectangle is (x^2 - 13x - 30).

If the width is (x + 2), the length is (x - 15).

• 5 days ago

area = length multiplied by width

so length = area / width

(x^2 -13x -30)/(x+2)= (x-15)(x+2)/(x+2) = x-15

so length = x-15

• 5 days ago

The square root of a piece of pie

• Philip
Lv 6
5 days ago

Every rectangle has a length, L and a width, W.;

Every rectangle has an area, A where A = L*W...(1);

Here we are given A = (x^2-13x-30) and W = (x+2).;

By (1), L = A/W = (x^2-13x-30)/(x+2)...(2);

We can factor A as (x+2)(x-15).;

Then (2) becomes L = (x+2)(x-15)/(x+2)...(3);

Clearly, for (x+2) =/= 0, (x+2) divides out in (3) giving L = (x-15).

• 6 days ago

A = lw

x^2 - 13x - 30 = (x + 2)l

x^2 - 13x - 30 = (x + 2)l

.........x^2 - 13x - 30

l = -------------------------

,,,,,,,,,,,,,x + 2

........(x -15)(x +2)

l = ----------------------

..............x + 2

l = x - 15 answer//

• 6 days ago

The area of a rectangle is (x^2 - 13x - 30).

If the width is (x + 2), the length is (x - 15)

• Ian H
Lv 7
6 days ago

The x + 2 factor cancels.

The answer is x - 15.

That is all.

• nbsale
Lv 6
6 days ago

First just factor the expression for the area:

x^2 - 13x - 30 = (x+2)(x-15).

So you divide that by x+2 and you get the length of x-15.

You have no information that lets you solve for x, but you know it must be > 15 since the length must be positive.

The question doesn't call for anything more than finding the expression for the length, x-15.

• 6 days ago

let length = ax + b

( ax + b ) ( x + 2 ) = x² - 13x - 30

By inspection ( using the first term and the last term ),

ax² = x², thus a = 1

2b = -30, thus b = -15

length = x - 15

• 6 days ago

Use can use long division.

.................x-15

......---------------

x+2|x^2-13x-30

.......x^2+2x

.......----------

.............-15x-30

.............-15x-30

.............----------

......................0

The length is x - 15.