SOLUTION: Solve. Remember to use the Rational Zero Theorem, Descartes' Rule of Signs, reduce to a quadratic, and then solve by using factoring or the Quadratic Formula. f(x) = x3 - 7x2 +

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: Solve. Remember to use the Rational Zero Theorem, Descartes' Rule of Signs, reduce to a quadratic, and then solve by using factoring or the Quadratic Formula. f(x) = x3 - 7x2 +      Log On


   

Question 737610: Solve. Remember to use the Rational Zero Theorem, Descartes' Rule of Signs, reduce to a quadratic, and then solve by using factoring or the Quadratic Formula.
f(x) = x3 - 7x2 + 15x - 25
Thank you!
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
See question #737608. Two of us answered that one which is identical to the current question. The other tutor seems to have removed his answer, not sure why.

Contrary to what I felt about my use of Rule of Signs, I handled the Descartes rule better than I felt at that time; I rechecked information about the rule.

My first root to test was a lucky guess, so immediately I found +5 as the only Real root. The other two in the resulting quadratic are complex with an imaginary component.