Answer:
the zeros are:
x=-4 and x = [tex]\sqrt{5}[/tex] and x= [tex]-\sqrt{5}[/tex]
Step-by-step explanation:
To find the zeros of x3 − 4x2 − 5x + 20 we need to factorize the equation, so we have:
actoring: x3+4x2-5x-20
Thoughtfully split the expression at hand into groups, each group having two terms :
Group 1: -5x-20
Group 2: 4x2+x3
Pull out from each group separately :
Group 1: (x+4) • (-5)
Group 2: (x+4) • (x2)
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Add up the two groups :
(x+4) • (x2-5)
Which is the desired factorization
Then, the zeros are:
x=-4 and x = [tex]\sqrt{5}[/tex] and x= [tex]-\sqrt{5}[/tex]
