{X+Y=95,40%X+78%Y=60%×65

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{X+Y=95,40%X+78%Y=60%×65{X+Y=95,40%X+78%Y=60%×65{X+Y=95,40%X+78%Y=60%×65X+Y=95,40%X+78%Y=60%×65X+Y=9

{X+Y=95,40%X+78%Y=60%×65
{X+Y=95,40%X+78%Y=60%×65

{X+Y=95,40%X+78%Y=60%×65
X+Y=95,40%X+78%Y=60%×65
X+Y=95,0.4X+0.78Y=39
0.4X+0.4Y=38------1式,0.4X+0.78Y=39----2式
2式-1式0.38Y=1
Y=50/19
代入X+Y=95,得
X=92又7/19

方程可以化简为
x+y=95
0.4x+0.78y=39
方程2减去方程1乘以0.4得到0.38y=1
所以y=2.63,代入求x即可