The number would be 18.
Half of 18 = 9
Two thirds of 18 = 12
9 + 12 = 21
Y = 3x + 1
Parallel lines have the same slope so the slope would be 3. Take the given equation and add the 3x to the other side. Using the given point. -2 (y point) = 3(-1(x point)) + b. Solve for b by adding the 3 over. b = 1 which is your y intercept.
