3x+4=6x-9 solve this and show the steps

Which of the following is the shape of a cross section of the figure shown below

Timmy uses 1 1 2 cups of sugar for every 2 gallons of lemonade he makes. how many cups of sugar would timmy use if he makes 13 gallons of lemonade?

What is the solution to this system of equations? y= 2x - 3.5 x - 2y = -14