题目内容
用心算一算.
(1)
-
-(-
)+(-
)
(2)-14-[2-(-3)2]÷(-
)
(3)化简求值.求:3a-3b+3[2a-(b-2a)]的值,其中a=-1,b=-2.
(1)
2 |
3 |
1 |
8 |
1 |
3 |
3 |
8 |
(2)-14-[2-(-3)2]÷(-
1 |
2 |
(3)化简求值.求:3a-3b+3[2a-(b-2a)]的值,其中a=-1,b=-2.
(1)原式=
+
-(
+
)
=1-
=
;
(2)原式=-1-(2-9)×(-2)
=-1-14
=-15;
(3)原式=3a-3b+6a-3b+6a
=15a-3b,
当a=-1,b=-2时,原式=-15+6=-9.
2 |
3 |
1 |
3 |
1 |
8 |
3 |
8 |
=1-
1 |
2 |
=
1 |
2 |
(2)原式=-1-(2-9)×(-2)
=-1-14
=-15;
(3)原式=3a-3b+6a-3b+6a
=15a-3b,
当a=-1,b=-2时,原式=-15+6=-9.
练习册系列答案
相关题目