SAT Mathematics Practice Test 4

The four-term polynomial expression can be factored completely, by grouping, as follows:(x3−5x2)+(2x−10)=0
x2(x−5)+2(x−5)=0
(x−5)(x+2)=0By the zero product property, set each factor of the polynomial equal to 0 and solve each resulting equation for x. This gives x=5 or x=±i√2,respectively.Because the question asks for the real value of x that satisfies the equation, the correct answer is 5.