The equation used to predict how long it will take to receive a package through the mail is ŷ=0.5 + 0.02x1 + 0.85x2 days, where
x1 is the distance to travel and x2 is the weight of the package. Use this equation to predict the how long it will take to receive a package that is 224 miles away and weighs 2.2 pounds.
Using the first equation: 4x = y + 3 ---> y = 4x - 3 We then substitute this into the second equation: 7x - 9(4x-3) = -2 ---> 7x - 9x + 27 = -2 ---> -2x = -29 ---> x = 14.5