解方程组:2(x +y)-3(x-y)=3;4(x+ y)+ 3(x-y)=15

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解方程组:2(x+y)-3(x-y)=3;4(x+y)+3(x-y)=15解方程组:2(x+y)-3(x-y)=3;4(x+y)+3(x-y)=15解方程组:2(x+y)-3(x-y)=3;4(x+y

解方程组:2(x +y)-3(x-y)=3;4(x+ y)+ 3(x-y)=15
解方程组:2(x +y)-3(x-y)=3;4(x+ y)+ 3(x-y)=15

解方程组:2(x +y)-3(x-y)=3;4(x+ y)+ 3(x-y)=15
是x=5 y=3

x+y=3.
解析:因为两个式子中都有3(x+y),且它们前面的符号相反,所以直接把两个等式左右相加,即6(x+y)=18,解得x+y=3