This week in pre calc 11 we learned how to solve equations using factoring. In the example 3x squared + 15x + 18 we start by checking for common factors. In this case we have a common factor of 3 making our question 3(x squared + 5x + 6)

Now that we have taken out the common factor we are left with an easier equation to solve. Next we look at 6 and find 2 numbers that multiply to it and add or subtract to 5x. There are two sets of  that multiply to 6 and add or subtract to 5, 2 • 3 and 6 •1

Since we have two possible answers the best thing to do is try both of them to see which one is correct. We start by taking our x squared + 2 + 3 + 6 and putting it into a box.

Now that we have a box we find common factors vertically and horizontally to find our equation

we see that we are left with (x + 2) (x + 3) as our answer. Now we need to foil it to verify our answer.

We have verified by foiling our answer and we got our original question which means our answer is right. One thing to remember is that if you take out a common factor at the beginning you have to show it in your answer so our final answer is 3(x + 2) (x + 3)