Help!!!! I will fan and give medals!!!! Help!!!

Find the zeros of the polynomial function.

f(x) = x2 + 9x + 20

Question

Help!!!! I will fan and give medals!!!! Help!!!

Find the zeros of the polynomial function.
 
 
        f(x) = x2 + 9x + 20

phi · Answer

I would try to factor it.

step 1:
list all pairs of numbers that when you multiply them, you get 20

can you do that ?

anonymous · Answer

anonymous · Answer

Notcie that
4+5=9
4(5)=20
Can you factor it now?

anonymous · Answer

i dont understand

anonymous · Answer

Notice that
$$
(a+x) (b+x)=x^2 +a x+b x+ a b=x^2+ (a+b)x+ a b
$$

anonymous · Answer

Your a=4 and your b=5

anonymous · Answer

$$
x^2+9 x+20=(x+4) (x+5)=0
$$
For which valuee your ploynomial is zero?

anonymous · Answer

Can you finish it?

anonymous · Answer

no ive never done this

anonymous · Answer

The zeros are x=-4 and x=-5. If you replace x by -4 or x by -5, your polynomial would be equal to zero

anonymous · Answer

A.
2, 10
 
 B.
–4, –5
 
 C.
–2, –10
 
 D.
4, 5

anonymous · Answer

$$
(-4)^2 + 9(-4) +20= 16-36 +20=0\
(-5)^2 + 9(-5) +20=25-45+20=0

$$

anonymous · Answer

so B.

anonymous · Answer

B is your answer

anonymous · Answer

Yes

anonymous · Answer

can you help me with more please

anonymous · Answer

Post it as new problem and tag me in it

anonymous · Answer

ok