How do you find the zeros of #y = (x + 2)(x − 4)(x + 1)#?

1 Answer
Jun 24, 2016

Answer:

#x=-2#, #x=4# and #x=-1#

Explanation:

A product of three numbers is zero if and only if at least one of the numbers is zero.

In our example:

#y = (x+2)(x-4)(x+1)#

So #(x+2)(x-4)(x+1)=0# if and only if at least one of the following holds:

  • #(x+2)=0color(white)(XX)# i.e. #x=-2#
  • #(x-4)=0color(white)(XX)# i.e. #x=4#
  • #(x+1)=0color(white)(XX)# i.e. #x=-1#

So the three zeros are: #x=-2#, #x=4# and #x=-1#