Like what you saw?
Create FREE Account and:
 Watch all FREE content in 21 subjects(388 videos for 23 hours)
 FREE advice on how to get better grades at school from an expert
 FREE study tips and eBooks on various topics
Solving Quadratic Equations by Factoring  Problem 3
Alissa Fong
Alissa Fong
MA, Stanford University
Teaching in the San Francisco Bay Area
Alissa is currently a teacher in the San Francisco Bay Area and Brightstorm users love her clear, concise explanations of tough concepts
Here’s a problem that I want to solve by factoring. What I’m going to be doing is looking for two numbers that multiply to +9 and add up to +6. That’s not too hard I know that’s going to be x plus 3 and x plus 3.
Now this is kind of strange because what I have is x plus 3 squared equal to 0 and I need to set each factor equal to 0 in order to solve for x but both the factors are the same that’s okay. What I have going on here is a problem where I have only one solution. The only solution comes from setting x plus 3 equals 0 because both my factors are the same. What this means is the only number that will make this statement true is the value 3.
Let’s just check and make sure that 3 does indeed work. 3 times itself is 9 plus, 6 times 3 plus 9 if that’s equal to 0 I’m a happy camper. 9 take away 18 plus 9 good, it does indeed equal to 0.
So this is a strange problem because I have only one solution, the way you might recognize this is if you are good at spotting perfect square trinomials. This is a perfect square trinomial because it comes from a binomial times itself. Anytime you have a perfect square trinomial it means you are only going to have one x solution.
Please enter your name.
Are you sure you want to delete this comment?
Alissa Fong
M.A. in Secondary Mathematics, Stanford University
B.S., Stanford University
Alissa has a quirky sense of humor and a relatable personality that make it easy for students to pay attention and understand the material. She has all the math tips and tricks students are looking for.
Your tutorials are good and you have a personality as well. I hope you have more advanced college level stuff, because I like the way you teach.”
Thanks alot for such great lectures... I never found learning this easier ever before... keep up the great work.... :)”
You seem so kind, it's awesome. Easier to learn from people who seem to be rooting for ya!' thanks”
Sample Problems (22)
Need help with a problem?
Watch expert teachers solve similar problems.

Solving Quadratic Equations by Factoring
Problem 1 15,194 viewsSolve by factoring:
x² + 4x = 0 
Solving Quadratic Equations by Factoring
Problem 2 12,276 viewsSolve by factoring:
x² + 2x = 15 
Solving Quadratic Equations by Factoring
Problem 3 11,065 viewsSolve by factoring:
x² + 6x + 9 = 0 
Solving Quadratic Equations by Factoring
Problem 4 11,216 viewsSolve by factoring:
3x² − 18x = 27 
Solving Quadratic Equations by Factoring
Problem 5 1,675 views 
Solving Quadratic Equations by Factoring
Problem 6 1,656 views 
Solving Quadratic Equations by Factoring
Problem 7 1,433 views 
Solving Quadratic Equations by Factoring
Problem 8 1,385 views 
Solving Quadratic Equations by Factoring
Problem 9 1,372 views 
Solving Quadratic Equations by Factoring
Problem 10 1,412 views 
Solving Quadratic Equations by Factoring
Problem 11 1,274 views 
Solving Quadratic Equations by Factoring
Problem 12 1,336 views 
Solving Quadratic Equations by Factoring
Problem 13 1,273 views 
Solving Quadratic Equations by Factoring
Problem 14 1,471 views 
Solving Quadratic Equations by Factoring
Problem 15 1,269 views 
Solving Quadratic Equations by Factoring
Problem 16 627 views 
Solving Quadratic Equations by Factoring
Problem 17 646 views 
Solving Quadratic Equations by Factoring
Problem 18 545 views 
Solving Quadratic Equations by Factoring
Problem 19 611 views 
Solving Quadratic Equations by Factoring
Problem 20 599 views 
Solving Quadratic Equations by Factoring
Problem 21 599 views 
Solving Quadratic Equations by Factoring
Problem 22 585 views
Comments (0)
Please Sign in or Sign up to add your comment.
·
Delete