2×(3x)=5x+12
x^5+x^4 = (x^3-x)(x^2+x+1)+x^2+x
1x+2x+3x+4x+5x+6x+7x+8x+9x+10x+11x+12x+13x+14x+15x=550
x+2x+3x+4x+5x+6x+7x+8x+9x=9x-8x-7x-6x-5x-4x-3x-2x-x.x等于多少?
(x+12)(x-2)+(x+7)(x+8)-(x+5)(x-10),其中x=2
解方程x/(x-2)=2x/(x-3)+(1-x)/(x-5x+6)
2x+3x+4x+5x+x+6x+7x=100
5x+9x=6x*2+12 x+9-x/3=4
x^3×x^5×x+(x^3)^12+4(x^6)^2=?
(5X-15)-(2X+3)=X+12
已知x -2x=5,求代数式x四次方+3x³-12x² -31x-15
5[x^2-x]=3[x^2+x]
2(x+5)^2-(x+6)^2-(x+2)(x-2)=42 (2x+1)(x-3)-(2x+3)(x-1)大于等于12