Answer:
Step-by-step explanation:
A) The dealer bought Birr 8000 at 7% tax.
Total amount to be paid = cost price (1 + r%)
r = 7% = 0.07
Total amount to be paid 
B) To find the VAT, it is the difference between the tax paid when the good was bought and the tax put on it after it was sold.
Tax paid when the shoes were bought = 7% of cost price

Tax paid when the shoes were sold = 9% of selling price

VAT = tax recovered on sale - Tax paid on purchase

You need to isolate x.
71 - 5x = 9x - 13
Add 13 to both sides.
84 - 5x = 9x
Add 5x to both sides.
84 = 14x
Divide both sides by 14.
6 = x
<h3>The answer is x = 6.</h3>
See attached picture for the answers:
6 (7x - 3)
You have to factor 6 out of 42x - 18.
Hope this Helps!!