Hi there! so lets break down this question, first we need to expand this into an equation we can solve!
When we expand
Now that we have this equation we can start to break down into something we can simplify/factor
\(x^4+6x^3+11x^2+6x−120=120−120 ,\\ x^4+6x^3+11x^2+6x−120=0\)
fun! now we have something we can factor,
\(x^4+6x^3+11x^2-120=0,\\ (x−2)(x+5)(x^2+3x+12)=0 \)
Now we can just look for what value of x makes this new equation equal to zero.
so we have to make it so that x equals a number that will turn the value into 0 or just set factors into 0.
I hope that this helps because I dont want to just hand you your answer! If you are still stuck just come back to this thread!
Hope you understand
~ Wolf :D