x^2+7x+12

(x+12)(x-2)+(x+7)(x+8)-(x+5)(x-10),其中x=2 -x^2+7x-12 (x-2)(x-3)+2(x-5)(x+6)-3(x^2-7x+12) (x+2)(x-12)+(x+7)(x+8)+(x+5)(x-10),化简. (x×x+3x+2)(x×x+7x+12)-24 1x+2x+3x+4x+5x+6x+7x+8x+9x+10x+11x+12x+13x+14x+15x=550 (（x²-5x+6)/(12-7x+x²))²÷((x²+3x+2)/(x
解分式方程(5-2x)/(x^2-x-12)=5x/(x^2+x-6)+(10-7x)/(x^2-6x+8)得 化简：9x-12x+5x,3x-5x-2+5x+8,3x+5+2x+3-7-11x 解方程x²+x-6分之5x+x²-x-12分之2x-5=x²-6x+8分之7x-10 解方程.（5x/x²+x-6）+（2x-5/x²-x-12）=7x-10/x²-6x+8 x=x/6+x/12+x/7+5+x/2+4=?