How do i do this, please explain.

Jada has a meal in a restaurant she adds up the prices listed on the menu for everything they ordered and gets a subtotal of $42.00. after tax the total is 45.99. what percentage of the subtotal is the total?

The approximate line of best fit for the given data points, y = −2x − 2, is shown on the graph. which is the residual value when x = –2? a)–2 b)–1 c)1 d)2

Can someone me with this graph problem by the way i need to know the answers by today since this assignment is due ! !