Week 15 – Math 11

This week in math 11 we learned how to add and subtract rational expressions. The first thing you are going to want to do when doing both adding and subtracting is to find the LCD (lowest common denominator), once you have found that you are going to want to re write the fractions and one big fraction with the LCD on the bottom. From there you will solve and when you get to the end you will reduce if possible.

For example if you have the equation First you will determine the LCD, in this case it would be so you will need to multiply the first fraction by 6y and the second fraction by x. This will leave you with now that both fractions are over the LCD you will need to check if you can reduce the fraction any lower and for this one you can’t so you would be done.

An example for subtraction would be the equation . For this you do the same by finding the LCD and for this one it would be so you will need to multiply the first fraction by x and the second one by z. This will now make one big fraction, but remember that the subtraction sign will need to be distributed to the 5z because it is not part of the original equation. Now you will have . Then you would to the same and look to see if you can reduce the fraction, once again you can’t so you would stop there.