求1800/x+1800/y=350 2400/x+1200/y=300 的解是多少
来源:学生作业帮助网 编辑:作业帮 时间:2024/08/27 11:55:32
求1800/x+1800/y=350 2400/x+1200/y=300 的解是多少
求1800/x+1800/y=350 2400/x+1200/y=300 的解是多少
求1800/x+1800/y=350 2400/x+1200/y=300 的解是多少
即36/x+36/y=7 (1)
8/x+4/y=1 (2)
(2)×9-(1)
72/x-36/x=9-7
36/x=2
所以1/x=1/18
1/y=(1-8/x)/4=1/7.2
所以x=18,y=7.2
一式乘以2得3600/x+3600/y=700 二式乘以3得7200/x+3600/y=900 两式相减得3600/x=200 得x=18带入一式,得y=7.2
1800/x+1800/y=350,两边同乘4得
7200/x+7200/y=1400 ①
2400/x+1200/y=300,两边同乘3得
7200/x+3600/y=900 ②
①-②得
3600/y=500
y=36/5
x=18
求1800/x+1800/y=350 2400/x+1200/y=300 的解是多少
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
y=2x*arctan(y/x),求y‘’
已知x-y=3,求[(x+y)(x-y)-(x-y)^2+2y(x-y)]除以的值
已知3x =2y 求x/x+y+y/x-y-y²/x²-y²
x+2y=2x+y+1=7x-y 求:2x-y?
x^2+y^2=15,x+y=7,x>y,求x-y
如果|X|=4 |Y|=2 且|X+Y|=X+Y 求X+Y
已知|x|=2,|y|=3,|x+y|=-(x+y)求x-y
f(x+y,x-y)=(x^2-y^2)/2xy,求f(x,y)!
求(X+Y)(X-Y)(X²+Y²),X=5 Y=2,
y=3(x-y),x=2(x-y)求x,y的值
f(x+y,y/x)=x^2-y^2求f(x,y)
已知x≠y,x^2-x=y^2-y,求x+y的值.
f(x+y,y/x)=x^2-y^2,求f(x,y),详见里面
(x-y)/(x+y)=3求( 3x-2y-1)/(x+y-5)
x,y 满足x(x-2)-y(y-6)=-10,求x,y的值
若x*x+y*y=x+y-1/2,求x,y的值如题