x-(30-x)=(30-x)-x/3,怎么解

(x+30)*(x-18)=x*x 3X+30+X+X-15=? x+35=(x+3x)*30% x-(30-x)=(30-x)-x/3,怎么解 x+3x-(9x+30x)=98 x-2/3x+x+2/7x=30 计算：(x+1)x=7 (x-1)(x+2)=30 (3-x)(3-x)+x=9 x-2/5x-(x-2/5x)2/3-(2/5x-1/3x)=30求x (x^2-3x+1) (x^2+3x+2)( x^2-9x+20)= -30求X 30/x=30/(x-1.5)-x 0.8x=x-30 x= x ( x-30)= -67.5 X=? x-30-0.2x=0.5x 60x（x-4)=30x 80%x+30-x=10%x X-30%X+8-X=20 30%x=50%x-20x (x+2)(x-3)>0这个不等式的解集是不等式组x+2>0 与 x+20 x-30}={x/x>3}.{x/{x+2