Question

How do you evaluate `frac { 18} { 20} - \frac { 5} { 6}`?

Answer 1

Convert the factions so that the denominators of both terms are identical, then perform the arithmetic on the numerators.
`18/20-5/6=color(red)(1/15)`

Explanation:

`18/20-5/6`

`color(white)("XXX")=(18 xx 3)/60-(5 xx 10)/60`

`color(white)("XXX")=54/60 - 50/60`

`color(white)("XXX")=(54-50)/60`

`color(white)("XXX")=4/60`

`color(white)("XXX")=1/15`