Question

PLEASE HELP, 5 STARS!!!
What are the domain restrictions of the expression y^2−3y−40y/y^2+9y+20 ?

Select each correct answer.

Answer 1

Y=-4 is one of your answers

Answer 2

Answer:

option D

Step-by-step explanation:

Domain is the set of x values for which the function is defined

To find domain restriction first we simplify the given expression

Factor both numerator and denominator

$\frac{y^2-3y-40}{y^2+9y+20}$

$y^2-3y-40=(y-8)(y+5)$

$y^2+9y+20=(y+4)(y+5)$

Replace the factors in our expression

$\frac{(y-8)(y+5)}{(y+4)(y+5)}$

Both top and bottom have y+5, so we cancel it out

$\frac{(y-8)}{(y+4)}$

To find restriction for y , set the denominator =0 and solve for y

$y+4=0$

so y=-4

y=-4 makes the denominator 0

So, y not equal to -4