1、计算(1)2/m+1/m (2)3b/xy-b/xy (3)(a/a+b)+b/a+b (4)(5x/2x-y)-x
1、计算
(1)2/m+1/m (2)3b/xy-b/xy (3)(a/a+b)+b/a+b (4)(5x/2x-y)-x+2y/2x-y
2、计算:
(1)2/-mn+10/mn (2)(2/x-1)-3/1-x
(3)(x+3/x+1)-(x-1/x+1)+x-2/x+1 (4)(t+4k/9k²-4t²)+k-t/4t²-9k²
注明:这里的/都表示分数线,每题至少2部.
3、先化简,再求值:y平方/y-2+4/2-y,其中y=-9/2