Answer :
3(n-5)+7y has 2 terms.
-2(3x+5)+10(a+b) has also 2 terms. Because they are doing distributive property, they only count as 1 term all together. :)
-2(3x+5)+10(a+b) has also 2 terms. Because they are doing distributive property, they only count as 1 term all together. :)