(1)(2x+3) 2 -25=0, 移项得,(2x+3) 2 =25, ∴2x+3=5或2x+3=-5, 解得:x 1 =1,x 2 =-4; (2) 2x 2 -7x-2=0, a=2,b=-7,c=-2, △=b 2 -4ac=49+16=65, x=
所以 x 1 =
(3)(x+2) 2 =3(x+2), 移项得,(x+2) 2 -3(x+2)=0, 因式分解得,(x+2)[(x+2)-3]=0, 解得:x 1 =-2,x 2 =1; (4)2x 2 +x-6=0, 因式分解得,(2x-3)(x+2)=0, ∴2x-3=0,x+2=0, 解得:x 1 =
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