Kenneth S. answered 02/01/18
Tutor
4.8
(62)
Calculus will seem easy if you have the right tutor!
You need to observe that the two numbers have a factor five in common.
Recognition, based on knowledge of factors of numbers, is a vital skill to be practiced.
75 + 20 = 5(15 + 4) =5(19) = 95, not surprisingly.