Question

1 over z - 1/2z - 1/5z = 10 over 21

Answer 1

\[\frac{1}{z}-\frac{1}{2z}-\frac{1}{5z}=\frac{10}{21}\]
Multiplying everything by 10z to get rid of the denominators we obtain:
\[\frac{10z}{z}-\frac{10z}{2z}-\frac{10z}{5z}=\frac{100z}{21}\]
\[10-5-2 = (\frac{100}{21})z \Rightarrow 3(21) = 100z\]
So z is just:
\[z=\frac{3(21)}{100} = \frac{63}{100} = .63\]

Answer 2

thanks!

Answer 3

hmm this isnt right it was supposed to be 3/97

Answer 4

Typing it directly into wolframalpha.com it gave me the same answer I gave you.