Question

what should be subtracted from the polynomial x^2-4x-6 so that 5 is a zero of the polynomial

Answer 1

p(x)=x^2-4x-6=0
let a be the number that should be subtracted

p(x)=x^2-4x-6-a=0
p(5)=(5)^2-4(5)-6=0
p(5)=5-6-a=0
a=-1

-1 should be subtracted from the given polynomial

Answer 2

p(x) = x^2-4x-6

the zero of the polynomial

x-5=0
x=-5

p (x)=x^2-4x-6

=(-5)^2 -4(-5) -6

=(-25)+20-6

=-31 + 20

= - 1 1