Factoring is used to solve quadratic equations in order to turn each term into zero to get a solution set. Using the form ax^2+bx+c=0, you need to figure out what numbers would equal c when they are multiplied while the same numbers will total the amount of b when they're added. An example would be 5x^2-5x-10=0.
5x^2-5x-10
5x(x-2)(x+1)=0
Because the a in ax^2 is equal to zero, 5x=0. Since x-2=0 and x+1=0 the solution sets are x=0, x=2, x=-1

How do I comment on this for a discussion question to the person that wrote this?

Question

Factoring is used to solve quadratic equations in order to turn each term into zero to get a solution set. Using the form ax^2+bx+c=0, you need to figure out what numbers would equal c when they are multiplied while the same numbers will total the amount of b when they're added. An example would be 5x^2-5x-10=0. 
5x^2-5x-10
5x(x-2)(x+1)=0
Because the a in ax^2 is equal to zero, 5x=0. Since x-2=0 and x+1=0 the solution sets are x=0, x=2, x=-1

How do I comment on this for a discussion question to the person that wrote this?

anonymous · Answer

Did the instructor or a student write this?

anonymous · Answer

a student....just not sure what to write here...to agree or not and to go into detail...I am not good with this stuff...

anonymous · Answer

The student explained the concept somewhat well.  They said that when looking to factor a quadratic, you should find two numbers whose product is c and whose sum is b.  Were you all supposed to mention if you have an a that doesn't equal 1?

Also, the student factored 5x^2 - 5x - 10 to 5x(x - 2)(x + 1) when it SHOULD be 5(x - 2)(x + 1).  Therefore, the solution set should be x = -1 or x = 2, not x = 0.

These are ideas, I'm not sure what else you could extrapolate from that answer.

anonymous · Answer

You could also point out that the a in ax^2 is not actually zero... it's five.

anonymous · Answer

ok...thank you so much!