How do I complete the square?

Completing the square is an algebraic method that can be used to solve a quadratic equation and find the coordinates of a turning point of a graph. Let's use x2 + 4x -5 = 0 are our example.First, half the coefficient of x, 4/2 =2 .Put this value inside brackets: (x +2), and square the brackets (x+2) 2Then, you need to subtract the square of the number you put in brackets, in this case 22 = 4 , so (x +2)2 -4 .Lastly, you just copy on the end the original third term, for us this is -5: (x+2)2-4 -5 This simplifies to (x +2)2 -9 =0 From this you can solve the equation for x (x= 1 or -5 ) and determine the coordinates of the turning point (-2,-9 )

Answered by Holly P. Maths tutor

2080 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Q = P / (R (4-t)), P=36, R= 3, t=-2


How would you work out the price of a trip if it is usually £24 but a man has a railcard that gives him 30% off?


The diagram shows the position of two ships, A and B, and a lighthouse L. Ship A is 5km from L on a bearing of 070° from L. Ship B is 3km from L on a bearing of 210° from L. Find the distance between A and B correct to 3.s.f.


The equation of line A is y = 6x -4. The equation of line B is 2y - 12x + 14 = 0. Are these two lines parallel?


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2024

Terms & Conditions|Privacy Policy
Cookie Preferences