Suppose corn chips cost 21.5 cents per ounce . If a bag cost $2.91, how many ounces of chips

If the cost to mail a package is an initial $5 and $0.28 for every pound the total cost to mail a package was $11.27, how much did the package weigh?

Can someone check if i did this correct. it’s number 4 if you’re wondering.

To solve the system of equations below, pedro isolated the variable y in the first equation and then substituted it into the second equation. what was the resulting equation? { 5y=10x {x^2+y^2=36