Question

The dimensions of a rectangle can be expressed as x + 3 and x - 8. If the area of the rectanlge is 60 square inches, what is the value of x?

Answer 1

X = 12

Explanation:

(x + 3) * (x - 8) = 60

x = -7 or x = 12

You can't have negative numbers

x = 12 I guess

I wan't sure how to explain that well sorry

Answer 2

12

Explanation:

Area of rectangle = product of dimensions

60 = (x + 3)(x - 8)

`x^2 + x(3 - 8) + 3 × -8 = 60 \\ x^2 - 5x - 24 = 60 \\ x^2 -5x -84 = 0 \\ x^2 - 12x + 7x - 84 = 0 \\ x(x - 12) + 7(x - 12) = 0 \\ (x + 7)(x - 12) = 0 \\ x = 12 or x = -7`

We cannot take x negative here , so x = 12