Please help! having a hard time with step functions!

The graph of fx shown below has the same shape as the graph of gx = 3x^2 but is shifted down 2 units

Write an expression that has three terms and simplifies to 4x - 7. identify the coefficient(s) and constant(s) in your expression

Julius sold five times as many computers as sam sold last year. in total, they sold 78 computers. how many computers did julius sell?