120 - 36 as a product with the GCF as a factor. True, we can factor out the GCF and we'll have a product:
GCF(120,36) = GCF(5(24),36)=GCF(5(12)(2),12(3)) = 12
We can factor that out and get:
120 - 36 = 12(10 - 3) = 12(7)
Answer: TRUE
How to find the GCF of three numbers.
There are a couple different ways; the obvious way is to find the GCF of the first two and then then GCF of the result and the third.
The other way is to prime factorize all three numbers; for each prime factor count how many times it occurs in each input. In the GCF it will occur the minimum of those three. Multiply the resulting powers of prime factors to get the GCF.
GCF(60,90) = GCF(30(2), 30(3)) = 30
60 + 90 = 30(2 + 3)
Xiao missed a factor of ten in the GCF.
