Write x^2+4x-12 in the form (x+a)^2+b where a and b are constants to be determined.

This method is known as completing the square. To find the constant a, we must halve the coefficient of x, which in this case is 4. This is to compensate for the double term when expanding the brackets. So a=4/2 =2. To find b, we subtract a^2 from the constant at the end of the expression, which in this case is -12. This is to compensate for the extra a^2 term that will appear once expanding the brackets. So b = -12 -2^2 = -12-4 =-16.

PG
Answered by Priya G. Maths tutor

5508 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

How do I expand the following equation (x+4)(x+2)


I am getting stuck on how to solve Simultaneous Equations, can you explain how to do this?


Solve the following equation: 13y - 5 = 9y + 27


Factorise 3x + 6


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