<span>An example of this might be 7 and 8. 7 multiplied by 7 to find the square root is 59, and 8 multiplied by 8 to find the square root is 64. 64 subtract 49 equals 25, so there you have your answer.</span>
The sum of the numbers 1-100 would be equal to the number of pairs (50) multiplied by the sum of each pair (101), or 50 x 101 = 5,050.
Answer:
64 is the right answer of your question
You're looking for the number 13 and 7 can go into.
You can use the listing method.
13: 13, 26, 39... and so on, and so on.
7: 7, 14, 21, 28, 35, 42, 49.... and so on.
An easier way to do it is to simply multiply 13 by 7.

13 and 7 can go into 91, evenly.
Hope this helped!