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

4891 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

The lines y = 3x² - x + 5/2 intersects the line y = x/2 +7 at two points. Give their coordinates. Show your working


Express [1+4(square root)7] /[ 5+ 2(square root)7] in the form m + n (square root)7 , where m and n are integers.


Write the complex number Z=1/2+sqrt(3)/2j both as a function involving cos & sin, and as a function involving an exponential.


How do I differentiate "messy" functions?


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