We look at four different word problems and write an equation for each. The first one involves the perimeter of a parallelogram. The second, area of a two-part rectangle. The third one has to do with the ages of two people – we know one is four times as old as the other, and 40 years older than the other. In the last problem, we’re given the aspect ratio and the perimeter of a rectangle, and the task is to find the side lengths.
For each problem, write a fairly simple linear equation and then solve the equation. I also solve some problems without the equation first – so you can see how the mental math or bar diagram solution steps match with the steps of solving the equation.
This lesson is meant for pre-algebra or for beginning algebra students.
See also my other pre-algebra videos at http://www.mathmammoth.com/videos/prealgebra/pre-algebra-videos.php