18.x-12-16.x-12=1
如果3x*x-x=1那么9x*x*x*x+12x*x*x-3x*x-7x+2001等于多少
x/2+x/8+x/12+x/20=1
解方程:2x(x-1)-x(3x+2)=-x(x+2)-12
x/2+x/6+x/12+x/20+x/30+x/42=1
1x+2x+3x+4x+5x+6x+7x+8x+9x+10x+11x+12x+13x+14x+15x=550
若x=π/3,|x+1|+|x+3|+...+|x+13|-|x+2|-|x+4|-...-|x+12|
1/6x+1/12x+1/7x+5+1/2x+4=x
先化简再求值:(x+2-12/x-2)/(4-x)/(x-2),其中x=-1/2
(x+12)(x-2)+(x+7)(x+8)-(x+5)(x-10),其中x=2
x*x+2x+x*x+10x+x*x+25+2x+x*x+1+1+16+x*x+4x*x+9-12x+16x*x+4-1
4/x+4=3/x+1/x+12
解不等式x/(x^2-7x+12)>=1