## Algebra: A Combined Approach (4th Edition)

$x^{2}+4x-10$ is impossible to factorize because we need two number whose product is -10 and sum +4 but 1,-10 -> -9 ( incorrect sum) 2,5 -> 7 (incorrect sum) -1,+10-> 9 (incorrect sum) -2,-5 -> -7 (incorrect sum) there is no correct sum so it is impossible to factor