Question

Which is a factor of 2a(cubed) - 2a(squared) - 7a + 7?
A) (a - 1)
B) (a + 1)
C) (a - 7)
D) (a + 7)

Answer 1

2a(cubed) - 2a(squared) - 7a + 7
= 2a^3 - 2a^2 - 7a + 7
= 2a^2 (a -1) - 7 (a -1)
= (a - 1)(2a^2 - 7)

(a - 1) and (2a^2 - 7) are factors 

answer
A) (a - 1)