解方程组1.x+1/3=5x-y/5 7y=5x+25 (x=2,y=5) 2.2x-y/5=x+y/3=3(x=8,y=1)
问题描述:
解方程组1.x+1/3=5x-y/5 7y=5x+25 (x=2,y=5) 2.2x-y/5=x+y/3=3(x=8,y=1)
答
1.(x+1)/3=(5x-y)/5 简化两边都乘以15得5x+5=15x-3y 再简化可得3y+5=10x (1)式7y=5x+25 (2)式(2)式两边乘以2减去(1)式可得:11y-5=50,可解得y=5,代入(1)式可得:3*5+5=10x,解得x=22.(2x-y)/5=(x+y...