Question

9/10 + 7/8 in simplest form

Answer 1

The answer is 31/40

because first you got cane both of the fraction to the same denominator. 

72/80 + 70/80

Add 72+70=142.

142/80 change it to an mixed number and it will be 1 31/40 in simplest form. 

Answer 2

You can say : 9/10 = 36/40   and    7/8 = 35/40 
so : 36/40 + 35/40 = 71/40= 1.775 and thats the simplest form :))
i hope this is helpful 
have a nice day