If a laptop originally costs $800, the balance due after the 10% discount and $150 gift card is applied is $.

If a laptop originally costs $800 at purchase, and is then discounted by 10%, the remainder would be $720, given that 10% of $800 is $80. Therefore, once then applying the credit card to reduce it another $150, the final price of the laptop would come out to $570 once the deductions are considered.

A= b/2 because u simplying both sides of equation