{2(x+3)≤ x+11
{2(x+3)≤ x+11
(2x-1)/(x-1)(x-2)=(x-5)/(x-2)(x-3) x/2x^2-11x-21=(x+7)/x^2-1
求x^2-3x/x^2-6x+9*x^2-11x+30/x^2-5x-1
解不等式(7x-11)/(2x-1)+3/(x-2)≤3/(x-2)+2
解不等式组:3/2x+5-1>2-x 2x+3≤x+11
1x+2x+3x+4x+5x+6x+7x+8x+9x+10x+11x+12x+13x+14x+15x=550
解方程x(2x-3)+3x+3x(x-2)=5x(x-4)+11
x-1)(X-2)(x-3)...(x-50)+x(x-2)(X-3)...(X-50)+...+x(x-1)(x-2)
x^2-3x
(x+3)(x-2)
3≤|8-x| |x+1|>2-x |x+3|7|x+1| x^2-6|x|+9>0 |x-1|+|x+2|≥5
x+2/x+1-x+3/x+2-x+4/x+3+x+5/x+4