SOLUTION: can someone help me solve this hard problem please! Thank you! =) Z^4+8z^3-9z^2=0

Algebra ->  Problems-with-consecutive-odd-even-integers -> SOLUTION: can someone help me solve this hard problem please! Thank you! =) Z^4+8z^3-9z^2=0      Log On


   

Question 404705: can someone help me solve this hard problem please! Thank you! =)
Z^4+8z^3-9z^2=0
Found 2 solutions by nerdybill, ewatrrr:
Answer by nerdybill(7384) About Me  (Show Source):
You can put this solution on YOUR website!
z^4+8z^3-9z^2=0
First, factor out what's common among all terms:
z^2(Z^2+8z-9)=0
factoring:
z^2(z+9)(z-1)=0
.
Solution:
z= {-9,0,1}

Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!


Hi

solving:

Z^4+8z^3-9z^2=0

z^2(z^2 + 8z - 9)= 0

z^2= 0   z= 0

(z^2 + 8z - 9)= 0

factoring

(z+9)(z-1)= 0 Note:SUM of the inner product(9z) and the outer product(-z) = 8z

(z+9)=0   z = -9

(z-1)= 0  z = 1