Question

If 4x² – 6x + m is divisible by x – 3, which one of the following is the greatest divisor of m ?

(a) 9 

(b) 12 

(c) 18 

(d) 36

Answer 1

(c) 18

If f(x) = 4x² – 6x + m is divisible by (x – 3), then f(3) = 0 

⇒ 4 (3)² – 6.3 + m = 0 ⇒ 36 – 18 + m = 0 ⇒ m = –18. 

The greatest divisor of m = 18.