To see if Ron-Jon is correct or not, we'll determine the slope of the line ourselves. We find the slope of a line by dividing the vertical change by the horizontal change between two points on the line. We can use the slope formula for this: Thus, we need to identify two points on the line.
The two points on the line are given as and . When we substitute them into the formula we get: It's a negative slope, because the line is sloping downward. The mistake Ron-Jon made was in calculating the slope. The points did not line up accordingly. The coordinates must be put into the slope formula in the correct order.