If a line has a point at (0,3), then it intercepts that point. This particular point has an x-coordinate of 0, which means that its y-intercept is the second co-ordinate, or the y-coordinate. The y-intercept for this line is 3. Then, we also know that it rises 3 units and runs 4. Well, this gives us the slope right there! As we know, the slope is rise over run, which is 3/4. So, the line's equation is
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As requested, here is the graph: