Question

How do you add `\frac { 9} { 7} + \frac { 7} { - 5}`?

Answer 1

`-4/35`

Explanation:

Note that the fraction `7/(-5)=(-7)/5=-7/5`

The negative sign is usually placed 'centrally' on the fraction.

We can express the sum as.

`9/7+7/-5=9/7-7/5larr "(positive)+ (negative)=negative"`

Before subtracting the fractions, we require them to have a `color(blue)"common denominator"`

This common denominator is 35

`rArr(9xx5)/(7xx5)-(7xx7)/(5xx7)=45/35-49/35=-4/35`