Answer :
Factors of 18: 1; 2; 3; 6; 9; 18
Factors of 27: 1; 3; 9; 27
GCF(18; 27) = 9
18 + 27 = 9 × 2 + 9 × 3 = 9 × (2 + 3)
Factors of 27: 1; 3; 9; 27
GCF(18; 27) = 9
18 + 27 = 9 × 2 + 9 × 3 = 9 × (2 + 3)
One possible answer is:
9×(2+3)
Explanation:
First we find the sum of 18 and 27. 18+27 = 45.
Next we find the GCF of 18 and 27. We do this by finding the prime factorization of each:
18 = 2*9
9 = 3*3
Thus, 18 = 2*3*3.
27 = 3*9
9 = 3*3
Thus, 27 = 3*3*3
We want the common factors; there are 2 3's in common, so 3*3 = 9 is the GCF. This makes the product 9×( ). The missing number would be 5, since 9*5 = 45. Writing this as a sum, we can use 2+3; this gives us 9×(2+3).
