4(x+2)² - 9(x-1)² = 0
(2x+4)² - (3x-3)² = 0
[ (2x+4)+(3x-3) ] [ (2x+4) - (3x-3) ] = 0
(5x+1)(-x+7) = 0
5x+1 = 0 或 -x + 7 = 0
x = -1/5 或 x = 7
4(x+2)² - 9(x-1)² = 0
(2x+4)² - (3x-3)² = 0
[ (2x+4)+(3x-3) ] [ (2x+4) - (3x-3) ] = 0
(5x+1)(-x+7) = 0
5x+1 = 0 或 -x + 7 = 0
x = -1/5 或 x = 7