Answer:
b is 45+63=9(5+7)
Explanation:
Once you know the GCF, you just need to find what the GCF (9 in this case), times what will get you 45 and 63. So we already know that 9 will be on the outside of the parentheses since it's what we're multiplying by. 9 times 5 is 45, so for the first number in the parentheses you'll put 5, and for the second, 9 times 7 is 63, so the second number in the parentheses is 7. You can check by solving it. 9(5+7). Use the distributive property and first you will do 9 times 5, which is 45, then 9 times 7 which is 63, so you'll get 45+63, which is correct.