十字相乘 3x^2+11x+10 ;5x^2+7x-6; 2x^2-7x+3; 3x^2-13x+10; 3x^2-13x-10; 6x^2-7x-5; 5x^2+6xy-8y^2
问题描述：
十字相乘 3x^2+11x+10 ;5x^2+7x-6; 2x^2-7x+3; 3x^2-13x+10; 3x^2-13x-10; 6x^2-7x-5; 5x^2+6xy-8y^2
答
3x^2+11x+10
=(3x+5)(x+2)
5x^2+7x-6
=(5x-3)(x+2)
2x^2-7x+3
=(2x-1)(x-3)
3x^2-13x+10
=(3x-10)(x-1)
3x^2-13x-10
=(3x+2)(x-5)
6x^2-7x-5
=(2x+1)(3x-5)
5x^2+6xy-8y^2
=(5x-4y)(x+2y)