题目内容
(1)计算:(
+
)(2-2
)-(
-
)2;
(2)
.
| 48 |
| 18 |
| 3 |
| 3 |
| 2 |
(2)
|
(1)原式=2
+2
-2
×
-2
×
-(5-2
)
=8
+6
-24-6
-5+2
=8
+6
-4
-29.
(2)由①得y=8-3x,③
将③代入②得4x-2(8-3x)=5,
化简得10x=21,所以x=
,
将上式代入③得y=8-3×
=
,
故原方程组的解为:
.
| 48 |
| 18 |
| 3 |
| 48 |
| 3 |
| 18 |
| 6 |
=8
| 3 |
| 2 |
| 6 |
| 6 |
=8
| 3 |
| 2 |
| 6 |
(2)由①得y=8-3x,③
将③代入②得4x-2(8-3x)=5,
化简得10x=21,所以x=
| 21 |
| 10 |
将上式代入③得y=8-3×
| 21 |
| 10 |
| 17 |
| 10 |
故原方程组的解为:
|
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