Answer:
Third Choice:

Step-by-step explanation:
One line has

The next line's reason is that b/2a was subtracted from both sides.
The missing line is:

Then it simplifies to

Answer:i have that same one
Step-by-step explanation:
Answer: 8x+15
Step-by-step explanation:
Answer:
c. 12
Step-by-step explanation:
To isolate the variable, you need to cancel out whatever's on the same side of the variable by using the inverse of the operation.
Hope this helps!! Have an awesome day φ(*^0^)