The slope of a line is a number that represents the direction and the steepness of the line. Or it is commonly defined as the rise over the run. It is denoted by the letter m. Let’s say that y is the rise and x is the run. A line may be increasing or decreasing just by knowing the slope. If the slope is a negative number, the line is decreasing, and if it is a positive number, the line is increasing. Here you have a slope of 1/20 and a rise of 6. The m is equal to 1/20 and y equals 6. So
m = y/x
1/20 = 6 /x
x = 6/(1/20)
x = 120