A. wall paper border costs $12.89 for a 15 feet roll. how many rolls do you need to purchase?

b. what would the total cost be?

(i have 7 feet by 3 inches for length and 8 feet by 3 inches of width

A:3 rolls B: $38.67

Step-by-step explanation:

1. Convert all units to the same value (feet to inches, as the opposite gives fractions)

2. Use new equation and multiply the said new variable (84*3 & 96*3)

3. The new total should amount to the total area (540)

4. Divide found area by 12 to convert back into feet (45)

5. Divide the feet by feet per roll (3)

6. Multiply for Cost

for this case we must apply distributive property to the following expression:

the distributive property states that:

then, when applying the property we have to multiply the -2 for each term within the parenthesis: