化简：3x²-[5x-(1/2x-3)+2x²]

(x-2)(x-3)+2(x+6)(x-5)-3(x²-7x+13)化简 x(x²-1)+2x²（x+1)-3x（2x-5)计算 (x+1-1/1-x)÷(x-x²/x-1) (x-4/x-x-6+ x+2/x-3)÷x+1/x-3 x+2/x+1-x+3/x+2-x+4/x+3+x+5/x+4 x^5+x^4 = (x^3-x)(x^2+x+1)+x^2+x 化简 (x+y)(x²-xy+y²) ； 3（2x-1）(x+6)-5(x-3)(x+6) 5x²+[x²+(5x²-2x)]-2(x²-3x),其中x=-1 (（x²-5x+6)/(12-7x+x²))²÷((x²+3x+2)/(x
计算：[(-5+x)(-x-5)]² (x+3)²-(x+2)(x-1) (3x-a)(3x+a)( -(x²-2x)+(-3x+2x²)化简! 6x+(2x²-3x)-(x²-1) （2x²-2x+3)(-x³+x-1)