Use factoring and the root method to solve the polynomial equation.
-$0.1 \mathrm { x } ^ { 3 } - 9 \mathrm { x } = 0$
A) $- 3 \sqrt { 10 } , 0,3 \sqrt { 10 }$
B) $- 9 \sqrt { 10 } , 0,9 \sqrt { 10 }$
C) $0,3 \sqrt { 10 }$
D) $- 9 \sqrt { 10 } , 9 \sqrt { 10 }$

Question

Quizplus · Accepted Answer

First, factor out an $x$, getting $x(0.1x^2 - 9) = 0$. This gives us one root, $x = 0$. For the quadratic, set $0.1x^2 - 9 = 0$, solve for $x^2$, getting $x^2 = 90$, and thus $x = \pm \sqrt{90} = \pm 3\sqrt{10}$.

Use Factoring and the Root Method to Solve the Polynomial 0.1x3−9x=00.1 \mathrm { x } ^ { 3 } - 9 \mathrm { x } = 00.1x3−9x=0

Use Factoring and the Root Method to Solve the Polynomial $0.1 \mathrm { x } ^ { 3 } - 9 \mathrm { x } = 0$