factor the following expression.\nx² + x - 90\n(x - ?)(x + )
factor the following expression.\nx² + x - 90\n(x - ?)(x + )
Answer
Explanation:
Step1: Find two - number product and sum
We need two numbers that multiply to - 90 and add up to 1. Let the two numbers be (a) and (b), so (ab=-90) and (a + b=1). The numbers are 10 and - 9 since (10\times(-9)=-90) and (10+( - 9)=1).
Step2: Factor the quadratic
For the quadratic expression (x^{2}+x - 90), we can factor it as ((x - 9)(x + 10)).
Answer:
((x - 9)(x + 10))