1.x²+5x+6
2.x²-5x+6
3.x²+5x-6
4.x²-5x-6
5.x²+7x+12
6.x²-7x+12
7.x²+8x+12
8.x²-8x+12
9.x²+13x+12
10.x²-13x+12
11.k²-2k+3
12.x²y²+5xy-6
13.x²y²+6xy-7
14.x²y²+9xy-20
15.-3+2xy+x²y²
因式分解 运用十字相乘法,并且一题中多次运用十字相乘法
1.x²+5x+6
2.x²-5x+6
3.x²+5x-6
4.x²-5x-6
5.x²+7x+12
6.x²-7x+12
7.x²+8x+12
8.x²-8x+12
9.x²+13x+12
10.x²-13x+12
11.k²-2k+3
12.x²y²+5xy-6
13.x²y²+6xy-7
14.x²y²+9xy-20
15.-3+2xy+x²y²