Question 655010
    The area of a rectangle is given by A = x2 – 2x + 30. Find the value of x if the total area of the rectangle is equal to 45 square units.
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{{{A = x^2 – 2x + 30}}}
since they give A as 45, substitute it in:
{{{45 = x^2 – 2x + 30}}}
{{{0 = x^2 – 2x + 15}}}
factoring:
{{{0 = (x+3)(x-5)}}}
x = {-3, 5}
throw out the negative solution (extraneous) leaving:
x = 5