You have the following expression:
36 + 45
In order to write the previous sum as the product of the GCF of the given number and another sum, you first find the prime factors of both numbers, just as follow:
- Prime factors of 36 are 2 x 2 x 3 x 3
- Prime factors of 45 are 5 x 3 x 3
The common products of the prime factors are 3 x 3 = 9. Then, 9 is the GCF of the two numbers.
Next, you use the GCF as the first factor of the product. The second factor is a sum of two terms, which are obtained by dividing each original term (36 and 45) by the GCF, just as follow:
36 + 45 = 9(36/9 + 45/9) = 9(4 + 5)
Hence, the required expression is 9(4 + 5)