Answer
Find out the what is the total cost of the computer .
To proof
As given
a computer costs $600.00
sales tax rate is 7.5 percent .
7.5 % is written in decimal form

= 0.075
Sales tax on the computer cost = 0.075 Ă— 600.00
= $45
Total cost of the computer = computer cost + sales tax cost
= 600.00 + 45
= $645.00
= $645
Therefore total cost of the computer is $645 .
Hence proved