You could take it the long way and plug in each x into the 4 equations to see which one puts out the exact y values. Another way you could do it is by finding the slope from two points using [tex] \frac{y_2-y_1}{x_2-x_1} [/tex]. For example, take (2,9) and (3,12). [tex] \frac{12-9}{3-2} =3 [/tex]. So the slope is 3, which rules out choices a and d. Now plug in 2 for equations b and c. Only equation b gives you an answer of 9, so the answer is b) y=3x+3
