Question

If (x + 1) is a factor of 2x³ + ax² + 2bx + l, then find the value of a and b given that 2a – 3b = 4.

Answer 1

Given that, (x + 1) is a factor of f(x) = 2x³ + ax² + 2bx + 1, then f(-1) = 0. [if (x + a) is a factor of f(x) = ax² + bx + c, then f(-) = 0]

Hence, the required values of a and b are 5 and 2, respectively.