x-30=80 把30移动到右边 x=80+30=110
x+30=80 解: x=80-30 x=50
答:x(34-3x)=8034x-3x^2=803x^2-34x+80=0(3x-20)(x-4)=0x1=20/3,x2=4
X-80=200-80 方程两边同时加80 x=200
(x+30)÷2=80 x+30=2*80 x+30=160 x=130
解:x+3x=804x=80 x=20 检验:把x=20代入左边,左边=20+3x20=20+60=80 右边=80 左边=右边 x=20是原一元一次方程的解.
x-60%x=80x-0.6x=80(1-0.6)*x=800.4x=80x=80÷0.4x=200
(x减5)4=80(解方程)(x减5)=20 x=20+5 x=25
(1)X-60% X=18, 40%x=18, 40%x÷40%=18÷40%, x=45;(2)35X+2.5*8=95, 35X+20-20=95-20, 35x÷35=75÷35, x=125;(3)40%X+30=80, 40%X+30-30=80-30, 40%x÷40%=50÷40%, x=125.
x/10-x/15=80通分:方程两边同乘以60,得:6x-4x=80*602x=4800x=2400 及时采纳啊,亲