Riddle 3 ***

[Ralle]

This is a hard one. What is the value of x that makes the ys equal?

y = 7 / (x - 5)
y = x^(1/2)
y = 3 / ( x^(1/2) )

 

[v3ck]

There is no value. Only x = 3 satisfies the lower two equations, which makes y = 3^(1/2) . However, 7/(3-5) = -3.5 .

 

[Robi]

0 i d say :?

 

[Ralle]

oh sry what I meant was. what's the y valueS that makes the form work?

 

[v3ck]

So you get:

x = (7 / y) + 5

x = y^2 for x ¡Ý 0

x = 9 / y^2 for x ¡Ý 0

Thus,

y^2 = 9 / y^2

y^4 = 9

y = 3^(1/2)

Therefore,

x = [3^(1/2)]^2 = 3

x = 9 / [3^(1/2)]^2 = 3

However,

x = 7 / 3^(1/2) + 5 = 9.041 . . .

7 / 3^(1/2) + 5

There is no solution.