Factorise x^2 +7x +10

First, you need to look at the x2 term and the number 10 - find all the factors of these numbersThe number before x2 is 1, and since 1 is a prime number, the only factor is 1. 1=1x1As for the number 10: 10 = 10x1 and 5x2.Now look at the symbol of the x term. It is a positive number. To make a positive number you must multiply either two positive numbers or two negative numbers.(will need the whiteboard to explain this properly)I use what I call the sausages method to work this out, I will need the whiteboard to explain this:Line up your numbers: When you are first learning you can guess the factors that will multiply to get what you need but over time I have found that students find it easier to see which factors are going to be important. Your AIM is to get to the number +7 - the x term.1 15 2 Cross multiply these terms (1x2=2 and 1x5 = 5). Write result under term.5 2 How can we use the numbers 5 and 2 to get to +7 - simple, 5+2.Therefore, the next part of the sausage comes into play - vertical, which is what the bracket is.(x+5)(x+2)

Answered by Sophie A. Maths tutor

2610 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

How do you expand brackets? eg. (2x+3)(3x+4)


A sequence increases by 5 each time and the first term is x. The sum of the first four terms is 54. Set up and solve an equation to work out the value of x.


How do you factorise the algebraic expression x^2 +5x+ 6?


Show that the following 2 lines are parallel: l1: 3y=15x+17 l2: 7y+5=35x


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