Question

Factor the expression. 21v2 – 70v + 49

A. 7(3v – 7)(v – 1)
B. (21v – 49)(v – 1)
C. 7(3v + 7)(v + 1)

Answer 1

A. 7(3v-7)(v-1)

Explanation:

21v2 - 70v +49

Factor out 7

7(3v2 - 10v +7)

write -10v as a difference

7(3v2 - 3v -7v +7)

Factor out 3v

7(3v × (v-1) - 7 × (v-1))

Factor out (v-1)

7(3v-7)(v-1)