题目内容
有理数a,b满足ab<0,则
+
+
=______.
| a |
| |a| |
| b |
| |b| |
| ab |
| |ab| |
∵ab<0,
∴a、b一正一负,
①当a>0,b<0时,
+
+
=
+
+
=1+(-1)+(-1)=-1;
②当a<0,b>0时,
+
+
=
+
+
=-1+1+(-1)=-1;
故答案为:-1.
∴a、b一正一负,
①当a>0,b<0时,
| a |
| |a| |
| b |
| |b| |
| ab |
| |ab| |
| a |
| a |
| b |
| -b |
| ab |
| -ab |
②当a<0,b>0时,
| a |
| |a| |
| b |
| |b| |
| ab |
| |ab| |
| a |
| -a |
| b |
| b |
| ab |
| -ab |
故答案为:-1.
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