问题
解答题
解方程:
(1)x2-9=0;
(2)x2+3x-4=0;
(3)x2-3x+2=0.
答案
(1)x2-9=0,
x2=9,
解得:x1=3,x2=-3,
(2)x2+3x-4=0,
(x-1)(x+4)=0,
解得:x1=1,x2=-4,
(3)x2-3x+2=0,
(x-1)(x-2)=0,
解得:x1=1,x2=2.
解方程:
(1)x2-9=0;
(2)x2+3x-4=0;
(3)x2-3x+2=0.
(1)x2-9=0,
x2=9,
解得:x1=3,x2=-3,
(2)x2+3x-4=0,
(x-1)(x+4)=0,
解得:x1=1,x2=-4,
(3)x2-3x+2=0,
(x-1)(x-2)=0,
解得:x1=1,x2=2.