Question

Solve by factoring:

x^2+2x+4x+8=0

Thank you!

Answer 1

x^2+2x+4x+8=0
x^2 + 6x + 8 = 0
You need to learn to do these by yourself. We know the first term must be x and x.
(x )(x ).
The last term must be 4x2 or 8x1 (since those are the only factors that will get 8). Which one gives a sum or difference of 6. It must be 4 and 2. So
(x 4)(x 2)
To get a positive sign in the middle term and a positive sign for the last term, we must have all + signs; therefore,
(x+4)(x+2) = 0
Now multiply the factors to see if you get the polynomial to check yourself.
I assume you can set each factor equal to zero and solve for the two roots. Here is a good web site for factoring "simple" polynomials. http://www.purplemath.com/modules/factquad.htm