Which equation is true when k = -15?

Apublic library wants to place 4 magazines and 9 books on each display shelf. the expression 4s+9s represents the total number of items that will be displayed on s shelves. simplify the expression

Solve these problems: 1.what is the perimeter of an equilateral triangle with sides measuring 6cm? 2. a regular pentagon has sides measuring 3.2 cm. what is its perimeter? 3. a regular decagon has sides of 3.5mm . what is it’s perimeter? 4. a regular octagon has a perimeter of 64cm. what is the length of one of the sides? 5. a regular hexagon has a perimeter of 72mm . what is the length of one of the sides? 6. what is the perimeter of a rhombus with sides measuring 11m?

Tony is charged $ 50 and additional $0.15 per miles for renting a car. a) represent the cost of renting a car with an equation,and the determine the cost if he drove it70 miles.b) what would be the cost of a car rental if the car was driven 250 miles? show work