作业帮(0.7X+0.6Y)/(X+Y)=66% [0.7(X-5)+0.6(y-5)]/(x+y-10)=66.25 % 奖励50000000000分
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(0.7X+0.6Y)/(X+Y)=66% [0.7(X-5)+0.6(y-5)]/(x+y-10)=66.25 % 奖励50000000000分
(0.7X+0.6Y)/(X+Y)=66% [0.7(X-5)+0.6(y-5)]/(x+y-10)=66.25 % 奖励50000000000分
(0.7X+0.6Y)/(X+Y)=66% [0.7(X-5)+0.6(y-5)]/(x+y-10)=66.25 % 奖励50000000000分
70%x+60%y=66%(x+y)
0.7x+0.6y=0.66x+0.66y
0.04x=0.06y
4x=6y
x=1.5y
70%(x-5)+60%(y-5)=66.25%(x+y-10)
0.7x-3.5+0.6y=0.6625x+0.6625y-6.625
0.0375x-0.0625y=-3.125
3/80x-5/80y=-25/8
0.3x-0.5y=-25
将x=1.5y代入上式,得
0.3*1.5y-0.5y=-25
0.45y-0.5y=-25
0.05y=25
y=500
x=1.5y=1.5*500=750
x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2
化简 x / y(x+y) - y / x(x+y) =
(0.7X+0.6Y)/(X+Y)=66% [0.7(X-5)+0.6(y-5)]/(x+y-10)=66.25 % 奖励50000000000分
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