Answer:
(a) 4
(b) 4 * (7+3)
Step-by-step explanation:
(a) Let's first start by prime factorizing (finding the prime factors) 28 and 12:
12: 2*2*3
28: 2*2*7
We can see here they both share a common factor of 2*2, which is 4, therefore the GCF is 4.
(b) Factor a 4 out from the equation:

This gives us:
4 * (7+3)
Answer:
The number of protons is the answer
Answer:
BCF and DCA
Step-by-step explanation:
Let e=erasers and p=pencils. So we know the total amount of erasers plus pencils sold is equal to 220. Therefore,

We also know the cost of erasers and pencils totaled to $695 in earnings and so:

and so those are your two equations.