It can be a positive or negative value. Find two points putting them in simple xy form. Calculating the Equation with One Point and the Slope 1 Plug the slope in for m in the formula y-y1 mx-x1.
Slope of the 2nd line.
Formula to calculate slope. Remember to include the right sign of the slope. Use a graph and two points to find slope without the equation handy. M -coefficient of xcoefficient of y.