Answer:
The step 4 is not what he should have done. But the wrong is step 5, because if he added -2x both sides, it would give the following equation:

and not 
Note that in step 4 he should have added 2x and not -2x to both sides, but we still have the equality. The problem is that step 5 is totally wrong.
I don't know what answer is expected to this question, but I would mark step 5, because this is mathematically wrong.
Solving the equation

Using distribution

Add
both sides


Add 12 both sides

Divide both sides by 5

Simplifying
-16 + 23 (-4) + -3
Multiply 23 x -4
Add -16 + -92=-108
Add -108-3= -111 <------Answer
Answer:
Step-by-step explanation:
C=0.14×7,200=1008
Nadia made a total of $1008 last week in commission sales
b). To express the total amount she made in 2011, we derive the formula below;
Total amount (2011)=Average weekly commission× number of weeks in 2011
where;
Average weekly commission=$1008
number of weeks in 2011=52
replacing;
Total amount (2011)=(1008×52)=52,416
The total amount Nadia in commission in 2011=$52,416