(1)去分母得:2-x=-1-2(x-3),
去括号得:2-x=-1-2x+6,
解得:x=3,
经检验:x=3是增根,
则原方程无解;
(2)原式=[a+b/ab]÷
a2−b2
ab=[a+b/ab]•[ab
(a+b)(a−b)=
1/a−b],
将a=13,b=12代入,得,原式=1.
(1)去分母得:2-x=-1-2(x-3),
去括号得:2-x=-1-2x+6,
解得:x=3,
经检验:x=3是增根,
则原方程无解;
(2)原式=[a+b/ab]÷
a2−b2
ab=[a+b/ab]•[ab
(a+b)(a−b)=
1/a−b],
将a=13,b=12代入,得,原式=1.