Find the value of x when 2x^2 - x - 6 = 0

2x2 - x - 6 = 0

This must first be factorised - I use the 'box method' when the reciprocal of x2 is >1. This is difficult to explain via writing but it involves a little trial and error.

2x + 3 --> (+3x)

x - 2 --> (-4x)

Therefore 2x2 - x - 6 = 0 can be factorised to give (2x+3)(x-2) = 0 - At this stage, you should multiply it out to check that you get the original equation. 

if 2x+3 = 0 --> 2x= -3 giving x = -3/2

if x-2 = 0  --> x = 2

Final check can be done by substituting each value of x into the original equation and ensuring the answer is 0.

GS
Answered by Gayathri S. Maths tutor

8198 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Find f^-1(x) for the following equation: f(x) = (12+x)/3


Find the area of a kite with length 12cm and height 6cm.


How can I solve equations like 2x + 3 = 8x + 21?


If we know that y is directly proportional to x and that when x=1, y=3, then what is the value of x when y=4?


We're here to help

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

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences