Help algebra 2...quadratic equation standard form/ and checking problem/solution

[kamaka]

how do i write these quadaratic equations in standard form...i know the equation/formula but it doesn't help geez...

-x^2=15
2x-x^2=1


And how do i check the solutions for this problem -x^2-2x+3=0 since we had to identify the roots of the quadratic equation...

thanks a lot..

 

[juvenilepunk]

I literally just did this in my math class as well. Not sure on the first part, for the second part I just plugged in the answer till it worked. Because our tests were multiple choice it made it very easy.

 

[kamaka]

Whats Runescape?? I only play aion

 

[Call Me God]

For the second one, you foil and get 2 answers in ()'s. After you have the two answers you should set both of them to 0, and solve for X in both equations.

Then I believe that is your answer. Not 100%, I did this so long ago I forgot some, and for the first one uhh just put it in standard form? I don't understand the trouble on that one.

 

[kamaka]

I literally just did this in my math class as well. Not sure on the first part, for the second part I just plugged in the answer till it worked. Because our tests were multiple choice it made it very easy.

omg your fucking lucky...my teacher sucks donkey balls...each of our assignments are worth 6 points max...even if there is 100 problems he only grades 6 so max you can get is 6/6 on each assignment and we have to show work and shit...

along with quizzes/tests we can never use notes not even equations...we have to like know it like wtf i cant do that..

 

[DropKick Murphys]

how do i write these quadaratic equations in standard form...i know the equation/formula but it doesn't help geez...

-x^2=15
2x-x^2=1

Standard form is ax^2+bx+c=0 yes?
If so I don't get how it's giving you a hard time....
First: -x^2 - 15 = 0
Second: -x^2+2x-1=0

And how do i check the solutions for this problem -x^2-2x+3=0 since we had to identify the roots of the quadratic equation...

Quadratic formula is the easiest way.
cba doing it out for you but it is (-b+or-sqrt(b^2-4ac))/2a

 

[juvenilepunk]

If you have a graphing calculator you can plug it into that using the y function tool, then press second graph and find the corresponding number to the number after the = sign.

 

[Call Me God]

Standard form is ax^2+bx+c=0 yes?
If so I don't get how it's giving you a hard time....
First: -x^2 - 15 = 0
Second: -x^2+2x-1=0

And uhh... I don't think A in standard form can be negative? Correct?

 

[DropKick Murphys]

And uhh... I don't think A in standard form can be negative? Correct?

Sure it can.

 

Sure it can.

Are you sure? I've always learned in the ax + by + c = 0 formula, A has to be positive.

 

[kamaka]

i get the a,b,c part but dont get how to do it after lol

 

[xeleration]

A is always depicted as positive in standard form, but it can be negative.

Have you ever used a diamond problem?