Answer:
see explanation
Step-by-step explanation:
to clear a square root on the denominator
Multiply the numerator and denominator by the square root, for example

=
×
=
X=22.5
I got that by writing the fraction 12/15 is equal to 18/x. To get 12 to 18 u have to multiply 12 by 1.5, so I do the same to 15 to find what x would be
I believe it is 1, but i'm not completely sure.