3 x y = 9 x z = 12 y z = 1 Divide by 3
x y = 3 x z = 4 y z = 1 / 3
x y = 1 / 3 Divide both sides by x
y = 1 / ( 3 x )
3 x z = 1 / 3 Divide both sides by 3 x
z = 1 / ( 9 x )
4 y z = 1 / 3
4 * 1 / ( 3 x ) * 1 / ( 9 x ) = 1 / 3
4 * 1 / ( 27 x ^ 2 ) = 1 / 3
4 / 27 x ^ 2 = 1 / 3 Multiply both sides by 27 x ^ 2
4 = ( 1 / 3 ) * 27 x ^ 2
4 = 27 x ^ 2 / 3
4 = 9 x ^ 2
9 x ^ 2 = 4 Divide both sides by 9
x ^ 2 = 4 / 9
x = + OR - sqrt ( 4 / 9 )
x = + OR - 2 / 3
For x = - 2 / 3
y = 1 / ( 3 x )
y = 1 / [ 3 * ( - 2 ) / 3 ]
y = 1 / - 2
y = - 1 / 2
z = 1 / ( 9 x )
z = 1 / [ 9 * ( - 2 ) / 3 ]
z = 1 / [ ( 9 / 3 ) * - 2 )
z = 1 / [ 3 * ( - 2 ) ]
z = 1 / - 6
z = - 1 / 6
For x = 2 / 3
y = 1 / ( 3 x )
y = 1 / ( 3 * 2 / 3 )
y = 1 / 2
z = 1 / ( 9 x )
z = 1 / ( 9 * 2 / 3 )
z = 1 / [ ( 9 / 3 ) * 2 )
z = 1 / ( 3 * 2 )
z = 1 / 6
You have two set of solutions :
x = - 2 / 3 , y = - 1 / 2 , z = - 1 / 6
and
x = 2 / 3 , y = 1 / 2 , z = 1 / 6
If 3xy = 9xz = 12yz = 1, what is the value of x, y, and z?
This is just a set of 3 equations:
3xy=1
9xz=1
12yz=1
⇒(18xyz)^2=1
⇒ xyz = ± 1/18
⇒ (x,y,z) = ±(2/3,1/2,1/6)
PLEASE TELL ME HOW DID THE SOLUTION CAME UP WITH xyz = ± 1/18 and (x,y,z) = ±(2/3,1/2,1/6. THANKS!
1 answer