Algebra 2

Solve: 0 = x3 + 5x2 + 2x – 8

Solve: 0 = x3 – x2 – 11x – 10

  1. 👍
  2. 👎
  3. 👁
  1. use your graphing calculator or plot it on a graph

    1. 👍
    2. 👎
  2. Use 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.

    1. 👍
    2. 👎
  3. x^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).

    1. 👍
    2. 👎

Respond to this Question

First Name

Your Response

Similar Questions

  1. How do I do this.?(Math.)

    Use the Substitution method to solve the system of equations. y - 2x = -5 3y - x = 5 Solve one of the equations for x or y. Let's solve the first one for y: y - 2x = -5 y = 2x - 5 Now let's substitute 2x - 5 for y in the second

  2. Math check please

    1. Solve the system of equations y=2x^2-3 y=3x-1 a)no solution b)(-1/2,5),(2,-5/2) c)(-1/2,-5/2),(2,5)**** d)(1/2,5/2),(2,5) 2. How many real number solutions are there to the equation 0=-3x^2+x-4? a)0 ***** b)1 c)2 d)3 3.solve

  3. Algebra

    To solve the system of equations, which expression could be substituted for x into the first equation? 3x-5y=14 x+4y=10 a)10-4y b)4y+10 c)(1/4)x+(5/2) d)(-1/4)x+(5/2) I have another problem just like this one so if you could

  4. Math help please

    1. Solve for x. 4(x - b) = x b = 4/3x b = 3/4x x = 4/3b x = 3/4b 2. Solve for y, then find the value of y when given x = 2. 6x = 7 - 4y -12 7/4 19/4 24 I need help solving these. Can you please explain how to solve these problems?

  1. Algebra

    Solve the given polynomial equation. Use the Rational Zero Theorem and​ Descartes's Rule of Signs as an aid in obtaining the first root. 2 x cubed minus 5 x squared minus 5 x minus 1 equals 02x3−5x2−5x−1=0

  2. Calculus

    Solve the quadratic equation by factoring. (Enter your answers as a comma-separated list.) 5x2 − 23x = −12

  3. math

    What is the first step in solving the linear system {2x − 3y = 11 {−x + 5y = −9 by the substitution method in the most efficient way? A. Solve the first equation for x. B. Solve the first equation for y. C. Solve the second

  4. Algebra

    Given the functions k(x) = 5x − 8 and p(x) = x − 4, solve k[p(x)]. k[p(x)] = 5x − 12 k[p(x)] = 5x − 28 k[p(x)] = 5x2 − 12 k[p(x)] = 5x2 − 28

  1. math

    Solve; 5X2 - 8 X + 3 = 0 using the quadratic formula . the 2 is second power

  2. Substitution Method-Plz help

    Use the Substitution method to solve the system of equations. x + y = -4 x - y = 2 solve for x in the second equation. x= y+2 Put that in for x in the first equation: x+y=-4 (y+2) + y = -4 solve for y. Then, x= y+2 i don't get

  3. math

    What is the first step in solving the linear system {2x−3y=11 {−x+5y=−9 by the substitution method in the most efficient way? A. Solve the first equation for x. B. Solve the first equation for y. C. Solve the second equation

  4. algebra

    solve for the indicated variable: a. temperature formula solve for F: K=5/9(F-32)+273 b. annual interest rate solve for R: A=P+Prt

You can view more similar questions or ask a new question.