10x2 + 3x – 4 = 0

(xvi) 10x² + 3x – 4 = 0 

Sol. 10x² + 3x – 4 = 0

∴  10x² + 8x – 5x – 4 = 0

∴ 2x (5x + 4) – 1 (5x + 4) = 0

∴ (5x + 4) (2x – 1) = 0

∴ 5x + 4 = 0 or 2x – 1 = 0

∴ 5x = – 4 or 2x = 1

∴ x = –4/5  or x = 1/2