taking LCM

4x² + 4ax + 2bx = - 2ab cross multiplying

4x² + 4ax + 2bx + 2ab = 0

4x(x + a) + 2b(x + a) = 0 taking 4x common from first two terms and 2b from last two

(x + a) (4x + 2b) = 0

(x + a) = 0 or (4x + 2b) = 0

Hence the roots of equation are