Step-by-step explanation:

Answer:
P = 12 + 5x
Step-by-step explanation:
P = a + b + c
P = 7 + (x + 4) + (4x + 1)
= 7 + x + 4 + 4x + 1
= 12 + 5x
Answer:
i think 9 but 6 could also be right
Step-by-step explanation:
18-12=6------18-3=15-------15-3=12-----------12-3=9
Find the area of the wheel:
Area of a circle is found using the formula:
Area = PI x r^2
9 inch would be the diameter, so the radius would be 9/2 = 4.5 inches.
The area would be 3.14 x 4.5^2 = 63.6 square inches.
Now divide the price by the area to get price per square inch:
Cost per square inch = 18.60 / 63.6 = $0.29 (rounded to the nearest cent)