9(x-3)²=25(x+4)²
9(x-3)²-25(x+4)²=0
[3(x-3)+5(x+4)][3(x-3)-5(x+4)]=0
(8x+11)(-2x-29)=0
x=-11/8 x=-29/2
3(x-3)=±5(x+4)
∴3x-9=5x+20 3x-9=-5x-20
x=-29/2 x=-11/8
9(x-3)²=25(x+4)²
3(X-3)=5(X+4)
3x-9=5x+20
2x=-29
9(x-3)²=25(x+4)²
9(x-3)²-25(x+4)²=0
[3(x-3)]²-[5(x+4)]²=0
(3x-9+5x+20)(3x-9-5x-20)=0
(8x+11)(-2x-29)=0
x=-11/8,x=29/2
3(x-3)=-5(x+4)或者3(x-3)=5(x+4)
解得:x=-11/8或者x=-29/2