# solve by factoring: 5t^2 - 10t = 0

#### Missy

##### New member
I want to know if I done this problem right because it just don't look right to me so I'm really not too sure

5t^2 - 10t = 0

This is what I did 5t^2-10t=0; 5t*t +5t *2 = 5t (t - 2); 5t^2 + 10t so the answer is 5t (t + 2)
the only thing that I can see that has changed is that there is now a (+) instead of a (-)
it may be right but I'm just not to sure. Could you check and tell me if I'm right or wrong and what should I do.
You guys are a big help to an old lady
Thank you,
Missy

#### Subhotosh Khan

##### Super Moderator
Staff member
Re: solve by factoring

Missy said:
I want to know if I done this problem right because it just don't look right to me so I'm really not too sure

5t^2 - 10t = 0

This is what I did 5t^2-10t=0; 5t*t +5t *2 <<<<< Why do you have a + sign there? You started with -

= 5t (t - 2); 5t^2 + 10t so the answer is 5t (t + 2)
the only thing that I can see that has changed is that there is now a (+) instead of a (-)
it may be right but I'm just not to sure. Could you check and tell me if I'm right or wrong and what should I do.
You guys are a big help to an old lady
Thank you,
Missy

#### stapel

##### Super Moderator
Staff member
Missy said:
This is what I did 5t^2-10t=0; 5t*t +5t *2 = 5t (t - 2)...
How did you get that (5t)(-2) equalled 10t? Shouldn't it have equalled -10t? :shock:

Eliz.