Answer:
a=-3/7 b=-2/8 c=-0.2
Step-by-step explanation:
The Percent Proportion is defined by. amount. ... The base, denoted by the letter b, is the entire quantity or total involved. Note: The number that is the base usually appears after the word of. The amount, denoted by the letter a, is the part being compared to the whole or total.
For this case we must simplify the following expression:
We eliminate the parentheses taking into account that:

So:

We add similar terms taking into account that:
Equal signs are added and the same sign is placed.
Different signs are subtracted and the major sign is placed.

Answer:

27 has to be C
I can't see the whole question for 28 and 29