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Help me please! LAST TWO QUESTIONS.

Help me please! LAST TWO QUESTIONS.-example-1
Help me please! LAST TWO QUESTIONS.-example-1
Help me please! LAST TWO QUESTIONS.-example-2

1 Answer

5 votes

Answer:

1)
(4x)(x+2)-x(3x+5)

2A)
w^2+3w

2B)
28\text{ in}^2

Explanation:

1)

First, let's write the expressions for the area of the entire shaded region and the white area.

The formula for the area of a rectangle is given by:


A=lw

For the entire shaded rectangle, the length is (4x) and the width is (x+2). So, the area is:


(4x)(x+2)

For the white rectangle, the length is (3x+5) and the width is (x). So, the area is:


x(3x+5)

The shaded area is the entire shaded rectangle minus the area of the white rectangle. Therefore, our expression would be:


(4x)(x+2)-x(3x+5)

2)

Part A)

So, we are given that the length of the rectangle is 3 inches greater than the width.

The area of a rectangle is given by:


A=lw

So, let w be width and let l be the length.

Since the length is 3 inches greater than the width, this means that the l is (w+3).

Thus, substitute. Our expression will therefore be:


lw\\w(w+3)

Since we want a polynomial, let's expand:


=w^2+3w

Part B)

To find the area when the width is 4, substitute 4 for w:


w^2+3w\\=(4)^2+3(4)

Square and multiply:


=16+12

Add:


=28\text{ in}^2

So the area is 28 square inches.

User Raph Levien
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