Answer:
To find the selling price of the laptop that costs R4 200 before VAT, we need to add 15% VAT to the cost.
The VAT amount can be calculated as:
VAT = 15% of R4 200
VAT = (15/100) x R4 200
VAT = R630
The selling price including VAT will be the cost of the laptop plus the VAT amount:
Selling price = R4 200 + R630
Selling price = R4 830
Therefore, the selling price of the laptop that costs R4 200 before VAT will be R4 830 after adding 15% VAT.