解方程组{x/2+y/3=2,2(x+y+1)=3(1-y)-15;
问题描述:
解方程组{x/2+y/3=2,2(x+y+1)=3(1-y)-15;
答
x/2+y/3=2
两边乘6
3x+2y=12 (1)
2(x+y+1)=3(1-y)-15;
2x+2y+2=3-3y-15
2x+5y=-14 (2)
(1)×5-(2)×2
15x-4x=60+28
11x=88
x=8
y=(-14-2x)/5=-6