Question

The area of a rectangle is 56 cm. The length is 2 cm more than x and the width is 5 cm less than twice x. solve for x. Round to the nearest whole number.

Answer 1

Answer: The answer is actually 6.

Explanation:

Answer 2

Area = L * W
Area = (x + 2)(2x - 5) = 56
x^2 +4x - 5x - 10 = 56
x^2 - x - 10 = 56
x^2 - x - 66 This does not factor nicely

You have to use the quadratic formula.
a = 1
b = - 1
c = - 66

x = (-b) +/- sqrt(b^2 - 4ac)
================
2a

x = 1 + /- sqrt(1^2 - 4(1)(-66)
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2(1)

= 1 +/- sqrt (265)
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2

= 17.279/2

= 8.639 which rounds to 9