Question #5119c

1 Answer
Nov 29, 2016

Let

3^x=7^y=63^z=k

So 3=k^(1/x)

7=k^(1/y)

and

63=k^(1/z)

=>3^2xx7=k^(1/z)

=>(k^(1/x))^2xxk^(1/y)=k^(1/z)

=>k^(2/x)xxk^(1/y)=k^(1/z)

=>k^(2/x+1/y)=k^(1/z)

=>2/x+1/y)=1/z

=>(2y+x)/(xy)=1/z

=>z(2y+x)=xy