5x-4x=2*1.8,5x-2+3x=3.6,x+4x=20.3,8x+10-3x=30,10.5-0.5x+0.5=1,x+2x+5x=10,解方程,

5x-4x=2＊1.8 x=3.6 / 5x-2+3x=3.6 8x=3.6+2 8x=5.6 x=0.7 / x+4x=20.3 5x=20.3 x=4.06 / 8x-10-3x=30 5x=40 x=8 / 10.5-0.5x+0.5=1 11-0.5x=1 0.5x=11+1 x=6/ x+2x+5x=10 8x=10 x=1.25 /0.8x-0.2+1.2x=1.8 2x-0.2=1...