## Ghatiii 3 years ago Solve: x2 - 20x + 36 = 0

• This Question is Open
1. Callisto

x^2 - 20x +36 = 0 x^2 -2x - 18x +36 = 0 x(x-2) -18(x-2) = 0 (x-2)(x-18) = 0 x-2 = 0 or x-18 = 0 <-solve these equations

2. MathLegend

Shouldn't you have walked her through from the beginning?

3. Callisto

To solve quadratic equations, you can do it like the above, that is factoring the expression on the left, put each factor = 0 and solve them OR Use quadratic formula.

4. MathLegend

You basically just gave out the answer.

5. Callisto

@MathLegend Did I? Where's the answer?

6. MathLegend

I said you basically did if you can read.

7. Callisto

The only mistake that I made here was not explain with words But basically, I did show the asker the way to work the answer out.

8. MathLegend

Yes, but my point is.. since she posted this. Don't you think she may need some explanation along the way?

9. MathLegend

Liek as you go from Step 1 to Step 2

10. MathLegend

Like*

11. Callisto

If that's what you want, x^2 - 20x +36 = 0 Split the middle term so that you can factor the expression easier x^2 -2x - 18x +36 = 0 Take out the common factor for the first two terms and last two terms x(x-2) -18(x-2) = 0 Take out the common factor again (x-2)(x-18) = 0 Put each factor = 0 x-2 = 0 or x-18 = 0 solve these equations on your own

12. MathLegend

Okay, I am just saying because a Mod told me that when I first joined.

13. Callisto

I'm sorry but I still don't think I'm giving the answer.

14. MathLegend

Okay. :)

15. monokerous

16. Yahoo!

Or.....Do u knw Quadratic Formuld..)) it will be very easy

17. Callisto

Just want to make few points clear. 1. If I was giving answer in the first post, I'm still giving answer in the second time I did it, even with explanations. 2. I didn't intend to give answers, as always. 3. I understand that I should have explained using words, but without using a word doesn't mean that I give answer. At least, I leave some steps for the asker to do it. 4. If you have noticed since I've started typing in this post. After I left the first comment, I actually kept typing again as I found it is better to leave some words to the asker that I'm doing factorization, as you've seen above. I apologize that I didn't explain what I had done in the first post, but I still insist that I'm not giving answers.

18. Yahoo!

|dw:1346139489935:dw|

19. pratu043

$x = \frac{ -b \pm \sqrt{b ^{2} - 4ac} }{ 2a }$

20. pratu043

Where a is coefficient of x^2 b is coefficient of x and c is the constant.

21. monokerous

I would've just given the quadratic equation and left it at that but I think your reply was just fine. I thought it was good of you to add the explanation afterwards.

22. lgbasallote

i think what mathlegend was saying is not about the "annotations" but the "lack of interaction"