Answer:

Explanation:
The key to answering this question is combining like terms. Add or subtract the terms that have the same variable.
1) Let's start with finding all the terms that have a b and combine them - those terms would be -4b and -8b. Add their coefficients (the numbers in front of the variable).

2) Next, let's do the same with all the terms that have a c. In this case, those terms would be 8c and -2c. So, add their coefficients too:

2) Finally, combine the constants (the terms with no variables). Those numbers would be 12 and 6.

Thus, the answer is
.