Can someone help me with #1 so I can get the gist of it?

Which of the following expressions is equal to 2x^2+8

The price for gasoline is represented by the equation y=3.69x, where y represents the total price for x gallons of gasoline. on a graph, the number of gallons is represented on the horizontal axis, and the total price is represented on the vertical axis. determine whether each statement describes the graph of the equation. select true or false for each statement

X= 3y - 6 2x - 4y = 8 solve the system of equations using substitution. a) (-12,-2) b) (15,7) c) (21,9) d) (24,10)