well let's round. 90= 100, 75=80 that is how I face it. now 80 is 1/5 of 5/5= 100. so as a (%) we would sort it like:::: it is 80% out of +100 so he must have grown around 13%-16% due to him being 75kg in the past.
1) -28
2) +36
3) +14114
4)-129
5) - 8
(they are all correct up to this point)
Yes, 1--5 in sentences are all right
hope this helps
The sum is 61 for this equation.