Question

What is the value of x in the proportion below
`(5)/(7) = (x)/(21)`

Answer 1

Solve for x

`\begin{gathered} (5)/(7)=(x)/(21) \\ 5\cdot21=7\cdot x \\ 105=7x \end{gathered}`

Divide both sides by 7

`\begin{gathered} (105)/(7)=(7x)/(7) \\ x=15 \end{gathered}`

Answer: x = 15