1. It must be divisible by 2 and 3. It IS divisible by 2. it IS divisible by 3. No remainder.
2. Add the digits and see if the sum is divisible by 3. Apply this rule to both numbers. 3 is not a common factor.
3a. 639
3b. 1035
3c. 179
Answer:

Step-by-step explanation:
• 
Let's use FOIL (first, outer, inner, last) to solve this. We'll multiply the terms by one another in that fashion.

Rearrange in decreasing exponents.

Answer:
0.5 I think. because for every 2 on the x axis, it grows 1 on the y axis.