We can see this is a quadratic equation and c is the constant. What changes when we change the constant? It will change the h intercept which we can see is also known as a y intercept (the y axis is renamed as h).
You can also use graphs to visualize this, try changing the constant in the equation and you can see the y intercept change.
You would have to add 47.50 + 122 to get 169.5 dollars. to get the amount of money he made in the summer, you would have to multiply 169.5 by 2 which would equal 339 dollars. so he made 339 dollars over the summer :)
