Question 972885
Just help for (d), holes in the graph.


{{{ f(x)= (x^2+3x-4)/(x^2+9x+20) }}}


{{{((x-1)(x+4))/((x+4)(x+5))}}}
an obvious factor of 1 is present, making the function undefined for x=-4.


You did not identify the correct factor of 1 when you picked the "hole" at x=-5.