Question

The Area of a rectangle is 3x2 + 9x square inches. The length of the rectangle is 3x inches.

Answer 1

A=3x^2+9x   I'm assuming is the equation for the area? with x being squared

L=3x

W=??

since we know the basic formula of area to be A=W*L, we can move it around to solve for W and get A/L=W. From here we can plug in the known values of A and L to solve for W.

A/L=W

(3x^2+9x)/(3x)=W

(3x(x+3))/3x=W

x+3=W

this gives you x+3=W, as both terms in the numerator contain 3x, which is the denominator.

specifically, I'd answer the questions like this.

1. To find the area of a rectangle, you must multiply the length times width

2. To find the width of a rectangle knowing the area and length, you must solve for the width using the formula for area by plugging in the known values for area and length

3. Work shown above

Answer 2

Width of the rectangle is x + 3 in

Step-by-step explanation:

• Step 1: Given area of the rectangle = 3x² + 9x in². Length = 3x in. Find width.

Area = length × width

3x² + 9x = 3x × width

∴ Width = 3x² + 9x/3x = x + 3 in