SOLUTION: Factor 20z^5 - 95z^4 + 60z^3

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: Factor 20z^5 - 95z^4 + 60z^3      Log On


   

Question 105104: Factor
20z^5 - 95z^4 + 60z^3
Answer by HyperBrain(694) About Me  (Show Source):
You can put this solution on YOUR website!
20z%5E5-95z%5E4%2B60z%5E3=z%5E3%2820z%5E2-95z%2B60%29
____________________=5z%5E3%284z%5E2-19z%2B60%29
Since we have produced 4z%5E2-19z%2B60, read my lesson entitled,"Factoring trinomials: SHORTCUT!!!" then go back to this page!
By the quadratic formula,
z=%2819%2B-sqrt%2819%5E2-4%2A4%2A60%29%29%2F%282%2A4%29
z=%2819%2B-sqrt%28361-960%29%29%2F%288%29
If you continue, z will be imaginary because of this part: sqrt%28361-960%29=sqrt%28-599%29
Therefore, this cannot be factored further.
So,
20z%5E5+-+95z%5E4+%2B+60z%5E3=5z%5E3%284z%5E2-19z%2B60%29

Power up,
HyperBrain!