Answer:
In standard form, your answer would be y = -0.5x - 2.5.
Step-by-step explanation:
If you put the points into the formula, (y2-y1)/(x2-x1), then you will be able to find the slope which is -0.5. Then, all that is needed is to find where the line that passes through both points passes through the y axis, which is -2.5.