]Answer:

Step-by-step explanation:
Substitute the value of the variable into the equation and simplify.

Solve it out.
Multiply / divide / add / subtract everything out.
Answer:
c
Step-by-step explanation:
Answer:
7x + 8 = 12 - 3x
Step-by-step explanation:
Answer:
a = 9
b = 6
I hope you can do the rest yoyrself, as I coulsnt find how to type it out ;-;