Friday

January 30, 2015

January 30, 2015

Posted by **Christian** on Sunday, January 13, 2008 at 7:42pm.

Solve: 0 = x3 – x2 – 11x – 10

- Algebra 2 -
**physics time..**, Sunday, January 13, 2008 at 7:57pmuse your graphing calculator or plot it on a graph

- Algebra 2 -
**Count Iblis**, Sunday, January 13, 2008 at 8:05pmUse the Rational Roots Theorem.

Suppose

a x^n + b x^(n-1) + .... e = 0

If x is a rational number of the form p/q with p and q integers that don't have factors in common (i.e. the fraction p/q is simplified as much as possible), then p must divide e and q must divide a.

In case of the equation:

x^3 + 5x^2 + 2x – 8 = 0

this means that x = integer that divides 8. x = 1, x= -2 and x = -4 are solutions.

- Algebra 2 -
**Count Iblis**, Sunday, January 13, 2008 at 8:20pmx^3 – x^2 – 11x – 10 = 0

Assuming again that the roots are rational numbers, it follows from the Rational Roots Theorem that the roots are integers that divide the number 10.

So, the only possible rational roots are:

x = -10, x = -5, x = -2, x = -1, x = 1, x = 2, x = 5, x = 10

Only x = -2 satisfies the equation.

Factoring the polynomial gives:

x^3 – x^2 – 11x – 10 =

(x+2)(x^2 -3x - 5)

The zeroes of the quadratic factor are the other zeroes (you already know that they cannot be rational).

**Answer this Question**

**Related Questions**

Intermediate Algebra - Combine like terms: -3x^2+2x-4x^2-9+6x-2x^2+8 Solve for x...

algebra - Solve with fractions. 6x^(2/3)-11x^(1/3)+4=0 How do I solve? Thanks

Algebra 2 Help! - 1.) Simplify the expression. [sqrt3 + 2i][sqrt3 - 2i] 2.) ...

algebra PLZ HELP!!! - y= 9/11x-17 9x-10y=179 You need to use parentheses to tell...

algebra - solve for x 8x - 11 = -11x + 18

algebra - -6-11x=-136 solve

9th Grade Algebra - 4x^2-11x+3=5x+4 How do I solve this?

college algebra - Solve for 3x + 6Y - 9z = 3 5x - 7y + 10z = -4 11x +4y - 6z = 2

Algebra......Help Quick!! - 12a^3bc-18a^2bc^2+6a^2c, x^2+20x+36, 12x^4-8x^3-4x^2...

algebra - how do you solve polynomial equation by factoring 3x^4 + 11x^3 = 4x^2