Let's assume we were given 2 numbers: 15 and 30. Their sum is:

We want to express it as the product of GCF and another sum.
15 is divisible by: 1, 3, 5, 15
30 is divisible by: 1, 2, 3, 5, 6, 10, 15, 30
The greatest number that appears in 2 series is 15.


In this case sum of two numbers can always be written as:
Answer:
number 3
Step-by-step explanation:
(3,000+900+70) = 3,970
3,970*10 = 39,700
35.75
explanation-
3.90 ph x 7.5 hours = 29. 25
plus the gas can 6.50
29.25+6.50= 35.75