Final answer:
To solve the business owner's total payment for website-hosting services, the equation is set up by adding the one-time setup fee of $20 to the product of the monthly charge 'd' and the number of months, which results in a monthly charge of $10 for the service.
Step-by-step explanation:
The question has provided us with details about a website-hosting service's payment structure. We know there's a one-time setup fee of $20 and a monthly charge of d dollars. Given that a business owner paid $70 for the first 5 months of service, we can create an equation to represent the total cost C by adding the one-time setup fee to the sum of the monthly fees for 5 months:
C = setup fee + (monthly charge × number of months)
C = $20 + d × 5
Since the business owner paid a total of $70, we substitute C with $70 to get:
$70 = $20 + d × 5
To solve for d, we subtract the setup fee from both sides of the equation:
$70 - $20 = d × 5
Subtracting we get $50 = d × 5. Now, we divide both sides by 5 to isolate d:
$10 = d
Therefore, the monthly charge d is $10.