penyelesaian dari persamaan (9/25)^x2+4x × (125/27)^x+4

jawab

(9/25)^(x²+4x)  =  (125/27)^(x+4)
(3/5)^2(x²+4x) = (5/3)^3(x+4)
(3/5)^2(x²+4x) = (3/5)^-3(x+4)

2(x² + 4x) = -3(x+4)
2x² +8x = - 3x -12
2x² + 8x + 3x + 12 = 0
2x² +11 x + 12 = 0
(2x + 3)(x+4) = 0
x  = -3/2   atau x = - 4