раскроем скобки
15x+9x2-25-15x = x2+5x-5x-25-16x
8x2+16x = 0
8x(x + 2) = 0
x(x + 2) = 0
x1 = 0
x + 2 = 0
x2 = -2
раскроем скобки
15x+9x2-25-15x = x2+5x-5x-25-16x
8x2+16x = 0
8x(x + 2) = 0
x(x + 2) = 0
x1 = 0
x + 2 = 0
x2 = -2