Q. Rewrite the expression as a product of four linear factors:(x2−9x)2−2(x2−9x)−80Answer:
Define New Variable: Let's denote the expression inside the parentheses as a new variable to simplify the problem. Let u=x2−9x. The expression becomes:(u)2−2u−80
Factor Quadratic Expression: Now we have a quadratic in terms of u. We can factor this quadratic expression as we would normally do with any quadratic. We are looking for two numbers that multiply to −80 and add up to −2. These numbers are −10 and 8. So we can write: (u−10)(u+8)
Substitute Back and Simplify: Now we substitute back x2−9x for u to get the expression in terms of x: (x2−9x−10)(x2−9x+8)
Factor First Quadratic: Next, we need to factor each quadratic expression. Starting with x2−9x−10, we look for two numbers that multiply to −10 and add up to −9. These numbers are −10 and 1. So we can write:(x−10)(x+1)
Factor Second Quadratic: Now, we factor x2−9x+8. We look for two numbers that multiply to 8 and add up to −9. These numbers are −1 and −8. So we can write:(x−1)(x−8)
Write Original Expression: Finally, we write the original expression as a product of four linear factors: x - \(10)(x + 1)(x - 1)(x - 8)\