<PRE><B>Question 197798</B>
{{{f(x) = -5x + 2 }}} Start with the given function



{{{(f(x))^2 = (-5x + 2)^2 }}} Square both sides



{{{(f(x))^2 = (-5x + 2)(-5x + 2) }}} Expand. Remember something like {{{x^2=x*x}}}.



{{{(f(x))^2 = (-5x)(-5x) + (-5x)(2) + (2)(-5x) + (2)(2) }}} FOIL



{{{(f(x))^2 = 25x^2-10x-10x+4 }}} Multiply



{{{(f(x))^2 = 25x^2-20x+4 }}} Combine like terms.



So you were off by a sign...</PRE>