Solve the following equation: x^3 + 8x^2 + 4x - 48=0

To solve a cubic equation, you first have to guess at values for x that will solve the equation. Generally, it is good practice to start with 0, then use +/- 1, +/- 2 and so on until you find a value that works. For this particular question, the value x = 2 works to solve the equation. Following this, we factorise the solution out of the equation. i.e. as x - 2 = 0 for x = 2, we factorise (x - 2) out of our cubic equation. This gives us the following: (x-2)(x^2 + 10x + 24) = 0. We can then solve the quadratic equation that makes up the second term to find the remaining two solutions for the cubic equation. Using the quadratic formula to do so quickly, we find the remaining two solutions are x = -4 and x = -6. In summary, our three solutions are x = 2, -4 and -6.

RB
Answered by Richard B. Maths tutor

5009 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

What are volumes of revolution and how are they calculated?


I don't understand how to visualise differentiation, please could you show my an example to allow me to understand what it actually is better?


Find the gradient of the line Y = X^3 + X + 6 when X = 4


prove that lnx differentiated is 1/x


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2026 by IXL Learning