题目内容
计算与解方程
(1)(
-
)÷
(2)
-
=1.
(1)(
x+2 |
x2-2x |
x-1 |
x2-4x+4 |
x-4 |
x |
(2)
x+1 |
x-1 |
4 |
x2-1 |
(1)原式=[
-
]•
=
•
=
•
=
;
(2)方程两边同时乘以(x+1)(x-1),得:(x+1)2-4=x2-1,
即x2+2x+1-4=x2-1,
则2x-3=-1,
解得:x=1,
检验:当x=1时,(x+1)(x-1)=0,则x=1不是方程的解.
方程无解.
x+2 |
x(x-2) |
x-1 |
(x-2)2 |
x |
x-4 |
=
(x+2)(x-2)-x(x-1) |
x(x-2)2 |
x |
x-4 |
=
-3x |
x(x-2)2 |
x |
x-4 |
=
-3x |
(x-2)2(x-4) |
(2)方程两边同时乘以(x+1)(x-1),得:(x+1)2-4=x2-1,
即x2+2x+1-4=x2-1,
则2x-3=-1,
解得:x=1,
检验:当x=1时,(x+1)(x-1)=0,则x=1不是方程的解.
方程无解.
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