Does anyone know what graph is correct?

Marcus needs to rewrite f(x) = x2 + 6x + 4 in vertex form.

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

Rob spent 25%, percent more time on his research project than he had planned. he spent an extra h hours on the project. which of the following expressions could represent the number of hours rob actually spent on the project? two answers