Answer:
y = 3x + 9
Explanation:
The initial equation would be y = mx + b where m is the slope and b is the y-intercept. Then you would use the equation y^2 - y^1 / x^2 - x^1 to get the slope. Substituting the factors in it would be, 15 - 12 / 2 - 1 having a slope of 3. Then seeing as x is 0 y is 9, 9 must be the y-intercept.