Solve the quadratic equation x^2+5x+6=0

Quadratic equations are a slightly bit more tricky than other algebraic equations we might have seen before. They are called quadratic equations because one of the unknown values is squared (mutiplied by itself, e.g. 4^2=16). Importantly for us, this means there can be up to two possible roots of the equation. There are three main algebraic methods for solving a quadratic equation like this one; the method we will use is factorisation.
We want to simplify the expression x^2+5x+6 by factorising into two brackets.One bracket with have (x +- something) and the other (x+-something). These two somethings will multiply to make 6 and add to make 5. There is a little bit of trial and error involved in working about what these "somethings" are but if we have a basic understanding of factors, it is quite straightforward. The factors of 6 (in pairs) are 1, 6 2, 31 and 6 multiply to make 6 and add to make 7. 7 is not the coefficient of 5x so it is not this pair2 and 3 multiply to make 6 and add to make 5, which is the coefficient of 5x.Therefore, (x+2)(x+3)=0In order to satisfy this equation we need to find the values of x that make the result zero. To make the equation equal zero one (or both) of the brackets needs to equal zero. If x+2=0, x=-2 If x+3=0, x=-3Therefore x = -2 or -3

RW
Answered by Rob W. Maths tutor

2790 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

In 2017 the number of teachers in a school was 20. The number of teachers doubles each year. If in 2019 3/5 of the teachers are female how many male teachers are there in 2019?


Gemma wants to buy an equal number of pencils and rulers. Find how many of each she is able to purchase with £5. Use the price list below.


Solve the simultaneous equations, 5x + 2y = 20 , x + 4y= 13


The probability of pulling out a coloured counter from a bag is shown below: Green=0.2. Purple=0.15. Black=0.3. Pink=?. What is the probability of pulling out a pink counter?


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