We'll construct the equation in the form y = mx + b. Where m is the slope and b is the y-intercept.
We already know the slope, but we need the y-intercept. We can find the y-intercept by plugging in the ordered pair we have into our equation.
y = 2/3m + b
Plug in the values.
5 = (2/3)(-3) + b
Solve for b.
5 = (2/3)(-3) + b
5 = -2 + b
7 = b <-- Add 2 to each side
So, the equation would look like y = 2/3m + 7.