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 14,956 viewsSolve by factoring:
x² + 4x = 0 
Solving Quadratic Equations by Factoring
Problem 2 12,103 viewsSolve by factoring:
x² + 2x = 15 
Solving Quadratic Equations by Factoring
Problem 3 10,915 viewsSolve by factoring:
x² + 6x + 9 = 0 
Solving Quadratic Equations by Factoring
Problem 4 11,039 viewsSolve by factoring:
3x² − 18x = 27 
Solving Quadratic Equations by Factoring
Problem 5 1,592 views 
Solving Quadratic Equations by Factoring
Problem 6 1,570 views 
Solving Quadratic Equations by Factoring
Problem 7 1,369 views 
Solving Quadratic Equations by Factoring
Problem 8 1,317 views 
Solving Quadratic Equations by Factoring
Problem 9 1,303 views 
Solving Quadratic Equations by Factoring
Problem 10 1,340 views 
Solving Quadratic Equations by Factoring
Problem 11 1,199 views 
Solving Quadratic Equations by Factoring
Problem 12 1,240 views 
Solving Quadratic Equations by Factoring
Problem 13 1,209 views 
Solving Quadratic Equations by Factoring
Problem 14 1,375 views 
Solving Quadratic Equations by Factoring
Problem 15 1,193 views 
Solving Quadratic Equations by Factoring
Problem 16 552 views 
Solving Quadratic Equations by Factoring
Problem 17 578 views 
Solving Quadratic Equations by Factoring
Problem 18 489 views 
Solving Quadratic Equations by Factoring
Problem 19 554 views 
Solving Quadratic Equations by Factoring
Problem 20 538 views 
Solving Quadratic Equations by Factoring
Problem 21 537 views 
Solving Quadratic Equations by Factoring
Problem 22 502 views
Comments (0)
Please Sign in or Sign up to add your comment.
·
Delete