Let’s say you’ve got equation (1): 2y = 3x + 7 and equation (2): 5y -3x = 10. You can’t solve an equation with two variables in it so you need to eliminate one of the variables. One way to do this is to add 3x to equation 2 giving you 5y = 3x +10. Now if you do (2) – (1) you’ll get (2y – 5y) = (3x – 3x) + (7 -10) or -3y = -17. We’ve eliminated the x variable so now we’ve got a simple equation with one variable to solve and get y =17/3. Now that we’ve got a value for one variable we can sub the sub value into either equation to get another equation with one variable. Subbing into (1) gives 2 ×17/3 = 3x +7 which can be solved to give x = 9.
Hope this helps
Latest Answers