Answer :

Answer:

The zeroes of the given function are -5 and 4.

Step-by-step explanation:

The given function is

f(x)=x^2+x-20

Equate the given function equal to 0, to find the zeroes of the given function.

x^2+x-20=0

Write the middle term as 5x-4x.

x^2+5x-4x-20=0

(x^2+5x)+(-4x-20)=0

Taking out common factors from each parenthesis.

x(x+5)-4(x+5)=0

(x-4)(x+5)=0

Using zero product property, we get

x-4=0\Rightarrow x=4

x+5=0\Rightarrow x=-5

Therefore the zeroes of the given function are -5 and 4.