∴原式=
| a2 |
| 2a2−b(a+b) |
| b2 |
| 2b2−a(a+b) |
| (a+b)2 |
| 2(a+b)2+ab |
=
| 2a2b+a3−2ab2−b3 |
| (a−b)(2a+b)(2b+a) |
| a2+b2+2ab |
| 2a2+2b2+5ab |
=
| (a−b)(2ab+a2+b2+ab) |
| (a−b)(2a+b)(2b+a) |
| a2+b2+2ab |
| 2a2+2b2+5ab |
=
| 2ab+a2+b2+ab |
| (2a+b)(2b+a) |
| a2+b2+2ab |
| (2a+b)(2b+a) |
=
| 2a2+2b2+5ab |
| 2a2+2b2+5ab |
=1．