The ormula of a slope:
[tex]m=\dfrac{y_2-y_1}{x_2-x_1}[/tex]
We have the points (5, 2) and (9, y) and the slope m = 3.
Substitute:
[tex]\dfrac{y-2}{9-5}=3\\\\\dfrac{y-2}{4}=3\qquad\text{multiply both sides by 4}\\\\y-2=12\qquad\text{add 2 to both sides}\\\\\boxed{y=14}[/tex]
