Question

the width of a rectangle is 12 less than twice the length, and the area of the rectangle is 270m^2 what is the length of the rectangle?

Answer 1

Greetings!

Answer:

15m

Explanation:

Well, this can be shown using an equation:

2x- 12 = equation for width

x = equation for length

The area for a rectangle is width x length so:

(2x - 12) * x = 270

`2x^2 - 12x = 270`

Make the equation a quadratic:

2x² - 12x - 270 = 0

(÷2) = x² - 6x - 135

Now you need to find what values multiply to -135 and add to -6, in this case it is +9 and -15

(x + 9)(x - 15)

So x = -9 and x = 15

The length has to be 15 because the length cannot be a negative, so the length of the rectangle is 15m!

Hope this helps!