SOLUTION: Rewrite the middle term as the sum of two terms and then factor completely 4z^3 - 18z^2 - 10z

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Question 40765: Rewrite the middle term as the sum of two terms and then factor completely
4z^3 - 18z^2 - 10z
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Rewrite the middle term as the sum of two terms and then factor completely
4z^3 - 18z^2 - 10z

What you want are two expressions whose product is -40 and
whose sum is -18
The numbers are -20 and +2.
So replace -18z^2 with (-20z^2+2z^2)
4z^3 -20z^2+2z^2-10z
4z^2(z-5)+2z(z-5)
(z-5)(4z^2+2z)
2z(z-5)(2z=1)
Cheers,
Stan H.