Question

One factor of f(x)= 5x^3+ 5x^2- 170x+ 280 is (x + 7). What are all the roots of the function? Use the Remainder Theorem. x = –4, x = –2, or x = 7 x = –7, x = 2, or x = 4 x = –7, x = 5, or x = 280 x = –280, x = –5, or x =

Answer 1

Good job! The answer is B. (2nd option) Thanks! ;)

Answer 2

The roots are x = -7, 2 and 4.

Explanation:

5x^3+ 5x^2- 170x+ 280 divided by x + 7

= 5x^2 - 30x + 40

= 5(x^2 - 6x + 8) = 0

5(x - 4)(x - 2) = 0

x = 2, 4