To find the X intercept make y =0. Then factor out a negative on the side with the equation for each of the terms, so it becomes
0=-(x^2+x+3)
0=(x^2+X+3)
0-3=(x^2+X)
-3=x(X+1)
-3=X, X intercept -3,0
-3=(X+1)
-4=X, X intercept -4,0.
These are possible X intercepts you can check by using quadratic formula as well.
