Final answer:
To find the original cost of the laptop, set up and solve an equation using the discount and the total amount spent. The original cost of the laptop is $675.
Step-by-step explanation:
To find the original cost of the laptop, we can set up an equation using the information provided. Let's assume the original cost of the laptop is x.
Ms. Malia received a 10% discount, so the amount she paid for the laptop after the discount is 90% of x, which is 0.9x.
In addition to the laptop, she bought a mouse for $13.99, so the total amount she spent before taxes is 0.9x + 13.99.
We are given that the total amount she spent before taxes is $621.49. Therefore, we can set up the equation:
0.9x + 13.99 = 621.49
To solve for x, we can subtract 13.99 from both sides of the equation:
0.9x = 621.49 - 13.99
0.9x = 607.50
Finally, we divide both sides of the equation by 0.9 to solve for x:
x = 607.50 / 0.9
x = 675