.(2x+1)²-16=0
(2x+1)^2=16
2x+1=4 x=3/2
2x+1=-4 x=-5/2
25(x-1)^2=49
(x-1)^2=49/25
x-1=7/5 x=12/5
x-1=-7/5 x=-2/5
.
(2x+3)²=(-7)²
2x+3=7 x=2
2x+3=-7 x=-5
5(x+1)²-20=0
(x+1)^2=4
x+1=2 x=1
x+1=-2 x=-3
已知2a+1的平方根是±3,5a+2b-2的算术平方根是4,求3a-4b的平方根
(±3)^2=2a+1
2a+1=9
a=4
5a+2b-2=4^2
5*4+2b-2=16
b=-1
3a-4b=3*4-4*(-1)=16
16的平方根是±4
3a-4b的平方根±4