1、9（x+2）²-25=02、4（3x-1）²-9（3x+1）²=03、49（x-1）²-（1-2x）²=0

Question

1、9（x+2）²-25=0
2、4（3x-1）²-9（3x+1）²=0
3、49（x-1）²-（1-2x）²=0

Answer 1

1、9（x+2）²-25=0
（x+2）²=25/9
x+2=+-5/3
x1=-2+5/3,x2=-2-5/3
2、4（3x-1）²-9（3x+1）²=0
[2(3x-1)+3(3x+1)][2(3x-1)-3(3x+1)]=0
[2(3x-1)+3(3x+1)]=0,[2(3x-1)-3(3x+1)]=0
15x=-1 x1=-1/15,-3x=1 x2=-1/3
3、49（x-1）²-（1-2x）²=0
[7(x-1)+(1-2x)][7(x-1)+(1-2x)]=0
[7(x-1)+(1-2x)]=0,[7(x-1)-(1-2x)]=0
5x=6 9x=8
x1=6/5 x2=8/9