Area of a rectangle is A = L*W.
Here, A = 56 cm^2 (not 56 cm).
= (56 cm^2)=( L )( W ) = (x+2)*(2x-5) = 2x^2 - 5x + 4x - 10
Simplifying, 2x^2 - 5x + 4x - 10 = 56, or 2x^2 - x - 66 = 0.
Solve this using the quadratic formula:
-(-1) plus or minus sqrt ( (-1)^2 - 4(2)(-66) )
x = -------------------------------------------------------------
2(2)
Finish the work: find x. Most likely you will need to check both of the roots. Keep in mind that x will likely be a positive number.
