来自雷开彬的问题
【解方程组{x+y/3+x-y/2=1{4(x+y)-5(x-y)=1】
解方程组{x+y/3+x-y/2=1{4(x+y)-5(x-y)=1
1回答
2020-03-06 17:55
【解方程组{x+y/3+x-y/2=1{4(x+y)-5(x-y)=1】
解方程组{x+y/3+x-y/2=1{4(x+y)-5(x-y)=1
(x+y)/3+(x-y)/2=1(1)
4(x+y)-5(x-y)=1(2)
(1)×12
4(x+y)+6(x-y)=12(3)
(3)-(2)
11(x-y)=11
x-y=1(4)
代入(2)
4(x+y)=1+5(x-y)=1+5=6
x+y=3/2(5)
(4)+(5)
2x=5/2
x=5/4
(5)-(4)
2y=1/2
y=1/4
x=5/4y=1/4