解方程,九年级上册

9x눀-5=3
2025-12-15 06:33:16
推荐回答(1个)
回答1:

(1)
x²-7=0
x²=7
x1=√7 x2=-√7
(2)
x²+4x=0
x(x+4)=0
x=0或x+4=0
x1=0 x2=-4
(3)
x²-2x-1=0
x²-2x+1=2
(x-1)²=2
x-1=±√2
x1=1+√2 x2=1-√2
(4)
(x+1)²=121
x+1=±11
x1=-12 x2=10