How to explain 9/100+7/10=

First you need to find a common denominator.

in this case it would be 100.

so now you have 9/100 + 70/100

then you add the numerators and keep the denominator the same

9/100 + 70/100 = 79/100

you can not simplify this so that is your final answer

The answer is 0.709

9/100 = 0.09

7/10 = 0.7

So this answer is 0.79