Question

Algebra question

Answer 1

If you have a question like ax^2=ax+a

When you make it 0, shouldn't it be:

(ax^2-ax)/a = 0 and not, ax^2-ax-a = 0???

Answer 2

yes you got ax^2-ax-a = 0 which is correct !!!

Answer 3

Thats not my question, I'm saying why is it that instead of ax^2-ax/a = 0

Answer 4

Now divide each term by a so we get \[\frac{ ax^2 }{ a } \frac{ ax }{ a } - \frac{ a }{ a } = 0\]
now cancel out the common term in each fraction so we get
\[x^{2} - x - 1 = 0\] got it now ?

Answer 5

No, why is there an a there? ax^2-ax/a not ax^2-ax-a...=0

Answer 6

I don't think you understand my question :\, but thanks for trying @krishnashinde

Answer 7

If you did it your way it would be ax^2/a - ax/a = 0 and no a/a there.

Answer 8

Can you type your complete question so I can help ?

Answer 9

It's at the top, I don't know what you don't get it about it lol, I'm saying when you have a question like ax^2=ax+a and you want it to = 0, shouldn't it be (ax^2+a)/a instead of ax^2-ax+a. I don't know where you keep getting that extra a from.

Answer 10

@whpalmer4 Hey can you help me, I'm really confused with this?

Answer 11

Is your question is (ax^2 + ax)/2 ????

Answer 12

...

Answer 13

\[ax^2=ax+a\]What do you mean by "want it to equal 0"?

Answer 14

like a quadratic equation, how come when you set it = 0 it's ax^2 -ax-a = 0, instead of ax^2-ax/a = 0?

Answer 15

You can subtract \(ax\) from both sides, and subtract \(a\) from both sides:
\[ax^2-ax = ax-ax + a\]\[ax^2-ax = a\]\[ax^2-ax-a = a-a\]\[ax^2-ax-a=0\]

Answer 16

Is there specific reason we do it that way instead of dividing, or do we only divide when we look for a certain variable. Sorry this might be stupid question, just curious why it's like that.

Answer 17

You could also divide everything by \(a\) before doing anything:

\[ax^2=ax+a\]\[\frac{ax^2}{a}=\frac{ax+a}{a}\]\[\frac{\cancel{a}x^2}{\cancel{a}} = \frac{\cancel{a}x+\cancel{a}}{\cancel{a}}\]\[x^2 = x+1\]\[x^2-x-1=0\]

Answer 18

What do you propose to divide, exactly? The only thing you can divide and get a result of 0 is 0... So if you want 0 on the right hand side, and you have something else there, dividing isn't going to get the job done.

Answer 19

Let's take a simple case:
\[x = 3\]if we want a 0 on the right hand side, dividing won't do it, because there isn't anything we can divide 3 by that will give us 0, right?

Answer 20

OHHHH, I see, that makes a lot of sense, dividing would give 1 instead of 0.

Answer 21

We can subtract \(3\) from both sides:
\[x-3 = 3-3\]\[x-3=0\]

Or we could multiply both sides by 0, but that isn't very useful in solving the equation...
\[0*x = 3*0\]\[0=0\]got our 0 on the right side, though! :-)

Answer 22

I was being stupid I kept thinking, dividing by a, would give a 0. Thanks a lot for clearing that up, haha.

Answer 23

No problem, not a stupid question.

Answer 24

Thanks, you're the best!

Answer 25

Now there's a response that deserves a medal :-)