1.（x-3）方=4的根为：5 或1
2.x方-12x+18=-18
x^2-12x+36=0
（x-6）^2=0
x=6
3.-3+4x+4x方=0
4x^2+4x-3=0
4x^2+4x+1-1-3=0
(2x+1)^2-4=0
(2x+1+2)(2x+1-2)=0
(2x+3)(2x-1)=0
x=-3/2或x=1/2
4.2x方-3+1/8=0
16x^2-24x+1=0
16x^2-24x+9-9+1=0
(4x-3)^2-8=0
(4x-3+2√2)(4x-3-2√2)=0
x=3-2√2或x=3+2√2
5.x方-2x+3=（x-_1______)方+____2____
6.当x=______1___时,代数式x方-2x-3的值为-4
7.x方-x根6+___6/4_____=(x-__√6/2______)方
8.2x方+10x+__25/2__=2（x+___5/2_____）方