Question

How do you rewrite the expression `5/6=?/18`?

Answer 1

`15`

Explanation:

We get
`(5*3)/(6*3)=15/18`

Answer 2

The unknown value became `15`

Explanation:

The trick hear is to realise that if you multiply by 1 you do not change the value. Example: `6xx1=6`

But 1 comes in many forms. So we can change the way something looks without changing its intrinsic value.

`color(green)(5/6color(red)(xx1) color(white)("d") ->color(white)("d") 5/6color(red)(xx3/3)color(white)("d") =color(white)("d") (5xx3)/(6xx3)color(white)("d") =color(white)("d") 15/18`