1. ## Algebra factoring equations

2x^2+8x+8=0

25e^2+90e+81=0

The answers should be in x=? x=?

2. 2x^2+8x+8 = 0

2(x^2+4x+4) = 0

x^2+4x+4 factors into (x+2)(x+2)

2(x+2)^2= 0

X = -2

I don't know about the second one.

3. Originally Posted by Belanova
2x^2+8x+8=0

25e^2+90e+81=0

The answers should be in x=? x=?
In general, a^2 + 2ab + b^2 = (a + b)^2. So:

2(x^2 + 4x + 4) = 0 => 2(x + 2)^2 = 0 .......

(5e + 9)^2 = 0 ........

4. Thanks very much. What about these?
48q^2+168q+147=0
147r^2+126r+27=0

5. Originally Posted by Belanova
Thanks very much. What about these?

48q^2+168q+147=0 Mr F says: 3(4q + 7)^2 = 0

147r^2+126r+27=0 Mr F says: Take out a common factor (hint: 3) and write as a perfect square. Same as the others.
..

6. Wow, that makes those problems incredibly simple. I was never taught that, thanks.

Originally Posted by mr fantastic
In general, a^2 + 2ab + b^2 = (a + b)^2. So:

2(x^2 + 4x + 4) = 0 => 2(x + 2)^2 = 0 .......

(5e + 9)^2 = 0 ........

7. Originally Posted by coach2uf
Wow, that makes those problems incredibly simple. I was never taught that, thanks.
It only works for a quadratic trinomial that's a perfect square. That is, something that has the form $\displaystyle a^2 \pm 2ab + b^2$.