{x+y=60 {30%x+60%y=10%乘60

{x+y=60 {30%x+60%y=10%乘60怎么解,要过程(我们学了消元了)

1个回答

X+Y=60
0.3X+0.6Y=6 =>3X+6Y=60 => X+Y=3X+6Y => -2X=5Y => X=-5K;Y=2K
=> -5K+2K=60 =>-3K=60=> K=-20 =>(X,Y)=(100,-40)...ANS