(1)9x=25,x=25/9
(2)(2x-1)^2=9,2x-1=±3,2x=4或2x=-2,x=2或x=-1
(3)(x+1)^2=81,x+1=±9,x=8或x=-10
(4)(2x+3)^2=9,2x+3=±3,x=0或x=-3