Question

4+4=20 , 5+5=30, 6+6=42, 7+7=56, 9+9=?

Answer 1

4+4=20 --4*5=20 
5+5=30-- 5*6=30 
6+6=42-- 6*7=42 
7+7=56 --7*8=56 
8+8=72-- 8*9=72 
then, 9+9=90 --9*10=90

hope i helped....pls mark it as brainliest answer..!!

Answer 2

9+9= 90 may be this is the correct answer