Describe the process in proving that the solution of an inequality is valid.

Ok so you have to work backwards so lets say 
x=50 
work backwards does the answer you got make sense for it to be that answer 

Where m is the slope of the line and b is the y-intercept of the line, or the y-coordinate of the point at which the line crosses the y-axis. to write an equation in slope-intercept form, given a graph of that equation, pick two points on the line and use them to find the slope. this is the value of m in the equation.