x÷7=0.3 15-x=2 2.1÷x=3

0.3+0.3x=0.39 x= 2x-1.5x=7.6x x= 0.36x÷0.3=1.2 x=6（x+1.2)=18.6 x= 7x+2x = 8.1 x= (x-5）÷3=1.7 x=5（x+1.1)=15.5 x= 9x+25=70 x= 7x-4x=2.1 x= x÷7=0.3 15-x=2 2.1÷x=3 50+x-62,1.8x=7.2,2.1÷x=7,x÷7=0.3,x-4.5=6,15-x=8解此方程, X -1.8=4 X - 2=15 1.6X=6.4 X÷7=0.3 X÷3=2.1用关系式怎么解 化简 [3x/(x+2)-x/(x=2)]÷x/(x^2-4)化简 [3x/(x+2)-x/(x-2)]÷x/(x^2-4 设f(x)=x+2÷x(x 解方程：（x-3)÷2=7.5 3x+x=30 15x+x=40 2.5x-6=18.5 3x+7=59.2 8x-5.5x=7.57.2x÷3.6=2 3x＋6x-8x=0.7 12x-2x-5x=4.512x-x=0 5x＋x=1.8 3.2x＋1.8x=64.8x-0.8x=6 6.3-0.3x=9.6 8.6x-8.5x=0.720x-2x=36 9x＋6x=4.5 18x-12x=5.42x-1.6x=3.6 18x＋3x=7×6 1.2x-0.5x=0.71.3x＋2.7x=1 4x-3.2x=6.4 0.8x＋3.2x＋3x=562.8x-2x=7.2 4.2x-x=25.6 x÷7=2.1 (x²-x+1)÷(x²-x-1)=(x²+x)÷(x²+x-2)解方程 X^2-3X-2=0,求( x - 2x-1/x )÷(x-1)/(x^2-2x) (x+x)+(x-x)+(x*x)+(x÷x)=81 x-3/7x=x÷2+20 (5x+7x)÷2x= x/x-2+x-9/x-7=x+1/x-1+x-8/x-6, x/x-2+x-9/x-7=x+1/x-1+x-8/x-6, 解方程：8x -4.5÷0.2=16 3(x+30)=6x+30 3-(5-2x)=x+273x-(67-84x）-14=76 15-（7-5X）=2X（11-3X) X+(X+10)+(x+8)=36×3 11×（4-x)+15×（4-X）=30 先化简,再求值(x^2/x+2-4/x+2)÷2-x/x,其中x=-7/4