Question 263378
(x+2)(2x^2-3 x-4) = 0
there are several ways of veryfying that -2 is a solution
You can plug -2 in for x and see if the equation comes out equal
You can factor which I did.
and here are the other two solutions

by factoring 
*[invoke change_this_name4450 2, -3, -4, "x"]
and using the quadratic formula
*[invoke quadratic "x", 2, -3, -4 ]