Answer
$x=4$
Work Step by Step
Part A
$2x-1 = 7$
We should add 1 to both sides. $2x = 8$
We should divide both sides by 2. $x = 4$. 4 is the answer.
Part B. We could also take another approach.
We could subtract both sides by 7. $2x - 8 = 0$
Then we could subtract both sides by 2x. $-8 =-2x$
Then we would divide both sides by -2. $4 = x$. 4 is the answer.
Part C
The method in part A is clearly easier; there are fewer steps.