Answer:

Step-by-step explanation:
So, for 60 square feet they charge = 287
So, for 1 square foot they charge = 
If they charge the installation fee this becomes = 
We can write an equation to calculate cost by using this 
Where x is the amount of square foot
81 is the correct answer
hope it helps you have a good day
Answer
5x+y=8
Step-by-step explanation:
Answer:
x =12
Step-by-step explanation:
We can use the Pythagorean theorem to solve for x
a^2 + b^2 = c^2
16^2 + x^2 = 20^2
256 +x^2 = 400
Subtract 256 from each side
256-256 +x^2 = 400-256
x^2 =144
Take the square root of each side
sqrt(x^2) =sqrt(144)
x = 12
1. the last one
2.the first one hope this helps.