The equation of any straight line, called a linear equation, can be written as: y = mx + b, where m is the slope of the line and b is the y-intercept. The y-intercept of this line is the value of y at the point where the line crosses the y axis.
To calculate the travel speed per hour, divide 120 by 3. 120/3 = 40 mph. Now to calculate the time it will take to travel 200 miles, divided 200 by 40 mph. 200/40 = 5
