2.1X+7.9X=6.9

2.1X+7.9X=6.9 7.9 x+1.58+x=6.9x-8.42解方程 2.1X+7.9X=6.9 5X+0.8×2=7.12X+5.8=8.2 6X-3×4=1.2 3.6x*(2.1-x)=4.8x （X+X)+(X-X)+(X*X)+(X/X)=100 2.4x-x=2.1 x*x*x*x*x=80000? 2.1X+7.9X=6.9解方程.5X+0.8乘2=7.3解方程 7.9+1.58+x=6.9x-8.42方程解 x*x*x=504 x*x*x=504 （x+x）+(x-x)+(x/x)=11.2 f(x)=x,x x+x=x+15 X(X-1)=X 180=( )x( )x( )x( ) ×( ) 1.(x*2-3x+3)/(x*2-3x+2)-(x*2-5x+7)/(x*2-5x+6)-1/(x*2-4x+3)2.1/x(x+1)+2/(x+1)(x+3)+3/(x+3)(x+6) 3.已知：x*2-3x+1=0,求x*2+1/x*2. (x+30)*(x-18)=x*x x+ x+(x*50%)=1.5X?