for which values is this expression undefined?

Question

x-1/x^2-2x-3 + 5/2x^2+2x

Answer 1

for (x-1)/(x^2-2x-3) + 5/(2x^2+2x)

any value of x that makes a denominator = 0 makes the expression undefined

x^2 -2x -3 = 0

(x-3)(x+1) = 0

x= -1 or 3 make the expression undefined

2x^2+2x = 0

x(x+1) = 0

x= 0 and x=-1 make the expression undefined

x=0, -1 or 3 make the expression undefined