Answer:
13. 1
14. 42
15. 65
Explanation:
13.
If the average of two numbers is 1, then the sum of those two numbers is 2. As 2*1 is 2, and the average is found by dividing the sum by the amount of numbers.
Only one number is an integer and has a reciprocal that is an integer, the number being 1.
1/1 = 1
1/1 = 1
Average:
1+1 = 2
2/1 = 1
Therefore the answer is 1.
14.
If we multiply everything by 7x, we'd get
7 + x = 49
subtract 7 on both sides
x = 42
15.
If
pg = 50 and gr = 15
then
pg + gr = 65
factoring that would give you
g(p+r) = 65
I can't see 16 but good luck!