问题
解答题
(1)计算:-42×
(2)
|
答案
(1)原式=-42×
1 |
(-4)2 |
1 |
2 |
=-16×
1 |
16 |
1 |
8 |
=-1+(-1)
=-2.
(2)
2x+1 |
3 |
5x-1 |
6 |
去分母得:2(2x+1)-(5x-1)=6,
去括号得:4x+2-5x+1=6,
移项得:4x-5x=6-2-1,
合并同类项得:-x=3,
两边都乘以-1得:x=-3.
(1)计算:-42×
(2)
|
(1)原式=-42×
1 |
(-4)2 |
1 |
2 |
=-16×
1 |
16 |
1 |
8 |
=-1+(-1)
=-2.
(2)
2x+1 |
3 |
5x-1 |
6 |
去分母得:2(2x+1)-(5x-1)=6,
去括号得:4x+2-5x+1=6,
移项得:4x-5x=6-2-1,
合并同类项得:-x=3,
两边都乘以-1得:x=-3.