Answer:
Option C.
Step-by-step explanation:
The given equations are


We need isolate one of the variables, such that it appears by itself on one side of the equation.
Isolating a variable in two equations is easiest when one of them has a coefficient 1.
In equation 1, coefficient of B is 1. So, we can easily isolate one of the variables.
The equation is

Subtract 3A from both sides.

Multiply both sides by -1.

Therefore, the correct option is C.
The answer is 30 hope it helps
Im not sure if this is right but:
1. b
2. c
3. b
4. a
5. c
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