Hi there! so lets break down this question, first we need to expand this into an equation we can solve!
When we expand
x(x+1)(x+2)(x+3)=120
we get
\(x^4+6x^3+11x^2+6x=120\)
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