selesaikan persamaan kuadrat berikut dengan melengkapkan kuadrat sempurna. a. 4x^2 + 5x -3 = 0

jawab

4x² + 5x - 3 = 0
x² + 5/4 x - 3/4 =
x² + 5/4 x = 3/4
(x + 5/8)² = 3/4 + (5/8)²
(x + 5/8)² = 3/4 + 25/64 = 73/64
x + 5/8 = 1/8 √73
x = - 5/8 + 1/8 √73  atau x = - 5/8 - 1/8 √73
x = 1/8 (-5 + √73)  atau x = 1/8 (-5- √73)