Week 5- Pre-Calc 11

This week in Pre-Calc 11, we started our “solving quadratic equations”. We started off by reviewing and working on our factoring skills. In this blog post I am going to focus on how to factor a trinomial using the box method we have worked on throughout grade 10 and grade 11.

Essentially factoring is breaking an equation down to its prime form where the numbers now have nothing in common and can’t be broken down anymore.

Step 1: Write out your product and sum. How you get your product is multiplying the last number with the first, so in this case 5 and 3=15. And your sum is the middle number. Writing it out helps you not have to do so much mental math, which is where you will make errors.

Step 2: In this step you are going to determine what two numbers multiply to equal 15, but add to equal 16. So essentially what ever multiplies to equal your product needs to add to your sum. In this case 15×1=15, while 15+1=16.

Step 3: Now you’re going to draw your box and place the numbers in. The 1x and 15x doesn’t matter if they switch but the 5x^2 and the 3 need to be in the positions you see them in.

Step 4: Now you to determine what numbers you can put on the outside of the box that would multiply and give the product in the box. Sometimes this take trying out some numbers and then needed to change them before you’re done.

Step 5: This is your final step and it is writing out the final factored form of the equation.

And that’s all. A way to double check you did everything correct is to solve this factored equation and it should equal the equation you started with.