An employee at Shoes R Us gets a discount of 18% on all regular priced shoes. What is the proportional constant that can be used to calculate the the sale price (y) of any regular priced pair of shoes (x) that the employee purchases?

Exits on an interstate are numbered consecutively. the distance between exit 12 and exit 13 is 2.7 miles. the distance between exit 13 and exit 14 is 0.9 mile farther than the distance between exit 12 and exit 13. the distance between exit 13 and exit 15 is 6.8 miles farther than the distance between exit 12 and exit 14. the distance between exit 14 and exit 15 is miles.