已知(10y-3x)/(3x-y)=2 且x>0 求 ((15-8y)^(1/2))/((5x+4y)^(1/2))牛人速度来做是15-8y 不是15x-8y
问题描述:
已知(10y-3x)/(3x-y)=2 且x>0 求 ((15-8y)^(1/2))/((5x+4y)^(1/2))
牛人速度来做
是15-8y 不是15x-8y
答
又遇到盗版书了,有没有公德心啊
答
(10y-3x)/(3x-y)=2
10y-3x=6x-2y
12y=9x
4y=3x
((15x-8y)^(1/2))/((5x+4y)^(1/2))
=[(15x-8y)/(5x+4y)]^(1/2)
=[(15x-6x)/(5x+3x)]^(1/2)
=3/2√2
=3√2/4
答
15-8y不可能做出来
显然都不是齐次的式子啦!!!!!!!!
是15x-8y
答
题目有问题吧,题应是((15x-8y)^(1/2))/((5x+4y)^(1/2))吧
10y-3x=6x-2y,y=3x/4
((15x-8y)^(1/2))/((5x+4y)^(1/2))=((15-6)^(1/2))/(5+3)^1/2
=3/2√2
答
(10y-3x)/(3x-y)=2
10y-3x=6x-2y
9x=12y
y=3x/4
((15-8y)^(1/2))/((5x+4y)^(1/2))
=[(15-8y)/(5x+4y)]^(1/2)
=[(15-6x)/(8x)]^(1/2)
15-6x>=0
x