​ Which domain restrictions apply to the rational expression?

To find the domain restrictions, we just need to find the values that make the denominator = 0

So

x^2 + 2x  - 3   =   0       factor

(x + 3) ( x - 1)  = 0

Setting  each fact or to  0   and solving for x we have that

x +  3  = 0                             x  - 1  = 0

x  = -3                                    x  = 1

So x cannot   equal  -3   or  1