帮忙解下列三道二元一次方程.help me~(1)x/5-y/2=-4 x/15-y/7=-3 (2)x+y=360 112%x
问题描述:
帮忙解下列三道二元一次方程.help me~(1)x/5-y/2=-4 x/15-y/7=-3 (2)x+y=360 112%x
(1)x/5-y/2=-4 x/15-y/7=-3 (2)x+y=360 112%x+110%y=400
(3)x+y/2+x-y/3=6 4(x+y)-5(x-y)=2
答
x=-195,y=-70
x=200,y=160
x=322/109,y=60/109大哥。。。。有 过程吗,???(1)x/5-y/2=-4等式两边乘以1/3得 x/15-y/6=-4/3①x/15-y/7=-3②由①-②=……(2) 112%x+110%y=400 可化为:1.12x-1.1y=400①由x+y=360等式两边同乘以1.1得:1.1x+1.1y=396③①+③=……(3)原方程组可化为:2x+y/6=6①, -x+9y=2②②等式两边同乘以2得:-2x+18y=4③由①+③得……①-②=……①+③=……①+③得……让我自己想吗????????????= =这只是很简单的加减算术啊。。。。计算下就知道了。。。