Question

A student uses the division shown to divide –3x4 15x3 – x 5 by x – 5, and concludes that x – 5 is not a factor of the polynomial. describe two errors the student made. is x – 5 a factor? explain.

Answer 1

The student used k = –5 instead of k = 5. And the student did not use a placeholder zero for the x2 term. Also, x – 5 is a factor because there is no remainder when the division is performed correctly.

Answer 2

Recognize that the student used k = –5 instead of k = 5.

Recognize that the student did not use a placeholder zero for the x2 term.

Conclude that x – 5 is a factor because there is no remainder when the division is performed correctly.