Question

x^4-4x^3+x^2+28x-56=0; √7 is a root

Find the solution set. HELP

Answer 1

factor it

Answer 2

do u know how to factor ?

Answer 3

?????? u there

Answer 4

@bless
Hints:
If you know that \(\sqrt 7\) is a root, and seeing that
1. the coefficients are all integers,
2. constant term has 7 as a factor,
you have a good reason to guess that -\(\sqrt 7\) is also a root.
So try factor of (x+\(\sqrt 7\))(x-\(\sqrt 7\))=(x^2-7) by synthetic division.
If it divides without remainder, you only have a quadratic to factor, if necessary.