Solve the following equation: x^(3) - 6x^(2) + 11x - 6 = 0

x3 - 6x2 + 11x - 6 = 0
Let (x-a)(x-b)(x-c) = x3 - 6x2 + 11x - 6=> abc = -6 and a + b + c = -6 From abc=-6, find the possibilities of their values: (1,2,-3), (1,-2,3), (-1,2,3), (-1,-2,-3), (1,1,-6), (1,-1,6), (-1,1,6) & (-1,-1,-6) Then find the sum of each set of brackets (making sure you do this for all of them):e.g. 1 + 2 + (-3) = 0 and (-1) + (-2) + (-3) = -6 Now, using a + b + c = -6, eliminate the values which do not work.
In this case, the only set that work are (-1,-2,-3) .
So, giving us (x-1)(x-2)(x-3) = 0
To find x solve each bracket:=> x-1=0, x-2=0 & x-3=0 => x=1, x=2 & x=3
Hence, these are the 3 values of x.
[=> means "implies"]

Answered by Ellie-May H. Maths tutor

5516 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

The points P (2,3.6) and Q(2.2,2.4) lie on the curve y=f(x) . Use P and Q to estimate the gradient of the curve at the point where x=2 .


How to write an algebraic fraction in a given form e.g. (3+13x-6x^2)/(2x-3) as Ax + B + C/(2x-3) where A, B and C are natural numbers


Solve the simultaneous equations, 2x+y-5=0 and x^2-y^2=3


An 1kg ball collides normally with a fixed vertical wall. Its incoming speed is 8 m/s and its speed after the collision is 4 m/s . Calculate the change in momentum of the particle. If the collision lasts 0.5 s calculate the impact force.


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo
Cookie Preferences