How do you find all zeros of the function #F(x)=2x^3-14x^2-56x-40# given 10 as a zero?

1 Answer
Nov 2, 2016

Answer:

The other two zeros are #-1# and #-2#

Explanation:

Since we are told that #10# is a zero, #(x-10)# must be a factor:

#F(x) = 2x^3-14x^2-56x-40#

#color(white)(F(x)) = (x-10)(2x^2+6x+4)#

#color(white)(F(x)) = 2(x-10)(x^2+3x+2)#

#color(white)(F(x)) = 2(x-10)(x+2)(x+1)#

So the other two zeros are #x=-2# and #x=-1#