I still dont get my answers clear Please clearly explain the

I still dont get my answers clear. Please clearly explain these problems.

2) For the rational expression (x^2 + 2x - 15) / (x^2 + 6x + 5) , what values of x are not included?

A car is 5 ft (60 in) high. You want to make a model at a scale of (1/8). How high in inches will e model be?

1) Scale ---> 1: 8

It means model would be 1/8th of size of actual object.

Model for 5ft car ----5/8 ft = 60/8inch = 7.5 inches

2) (x^2 + 2x - 15) / (x^2 + 6x + 5)

Vlues of x whihc make denominator equal to 0 are not inclued

x^2 +6x +5 =0

x^2 +5x +x + 5 =0

x(x+5) +1(x+5) =0

(x+1)( x+5) =0

x= -1 and x=- 5

So, x=- and x=-5 are not included in the values for rational function