问题
解答题
计算 (1)(-
(2)
|
答案
(1)原式=-
×5 7
-1 2
×1 2 5 7
=(-
-1 2
)×1 2 5 7
=-
;5 7
(2)原式=(
-1 2
)+(-1 2
-2 3
)+1 3 4 7
=-1+4 7
=-
.3 7
计算 (1)(-
(2)
|
(1)原式=-
×5 7
-1 2
×1 2 5 7
=(-
-1 2
)×1 2 5 7
=-
;5 7
(2)原式=(
-1 2
)+(-1 2
-2 3
)+1 3 4 7
=-1+4 7
=-
.3 7