Factorise 3x^2 + 15x

To factorise an equation you need to look for factors that all the elements of the equation (3x^2 and 15x) have in common. You can do this all at one or in steps, to start with you can see that both parts have x as a factor, this means you can rewrite the equation as x*(...), to find what is in the brackets you need to divide the original equation by x, which is: 3x + 15. Therefore you can write 3x^2 + 15x as x*(3x +15) instead (a partially factorised version). However this is not fully factorised as you can see the two elements still have a common factor of 3. Doing the same as before with the x, the original equation can be writen in a fully factorised form: 3x*(x+5). You can see that it is not possible to factorise it further as the elements within the brackets have no more common factors. 

EF
Answered by Eve F. Maths tutor

13110 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Calculate the area of a circle where the circumference of the circle and sides of the square are tangential at 4 points.


Whats the difference between the three main trigonometric functions?


Factorise fully: 3x - 9x^2


AQA, foundation 2016: Lee does a sponsored silence for 2.25 hrs. He is sponsored 80p per minute. How much does he raise?


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:

© 2025 by IXL Learning