TenMarks teaches you how to write and solve two step equations that contain fractions.
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Learn about Two Step Equations that Contain Fractions In this lesson let's learn how we solve two-step equations when we’re dealing with fractions. I'm going to teach you two methods but let's look at the problem first. The problem says the equation is q/15-1/5=3/5. You see I've got three fractions. Method one, let’s solve using fraction operations. What do I have? I have q/15-1/5=3/5. It looks like q has been divided by 15, that’s operation one then 1/5 had been subtracted to it. Let's undo the 1/5 first. I will add 1/5 to both sides. This will become 0, so q/15 will become equal to 3/5+1/5 is 4/5. Now, it looks like q has been divided by 15, so let's multiply both sides by 15. 15 and 15 are 1, so q will become or 4÷15 is 60/5 which is 12. It looks like q=12. That’s the answer for q. There is another way to do the exact same thing. The second way of doing it is by using the lowest common multiple. Instead of leaving them as fractions, let's convert them and get rid of the fractions. q/15-1/5=3/5, the lowest common multiple of these denominators is 15. So, let's multiply 15 on both sides. I'm just multiplying the right hand side and the left hand side by 15. What does this give me? 15×q/15 gives me q-15×1/5, 15×1 is 15/5 is 3, 3×15 is 45÷5 is 9, so q-3=9. I've got a normal single step equation now. I add 3 to both sides, what do I get? q=12. We get to the same answer. We essentially did the same thing. In one case we let the expression be in fractions. On the other side, we got rid of fractions by multiplying both sides by the lowest common multiple of the denominators. So, we only were left with this and we solved it.