How do I solve quadratic equation by completing the square : X^2 - 4X = 5

We have X2 - 4X = 5, write the expression on the left side as X2 - 2•2X = 5. Then we would need extra term 4 to complete the square, so adding 4 on the both sides gives us, X2 - 2•2X + 4 = 5 +4. Simplify further to get: (X-2)2 = 9 , take square root on both sides , X - 2 = ± 3 ⇒ X = 2 ± 3 . Therefore, X = -1 or X = 5 .

RK
Answered by Rabin K. Maths tutor

3349 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

Integrate (3x^2-x^3)dx


Find dy/dx when y=(3x-1)^10


Find the first derivative of f(x) = tan(x).


Why maths is so hard sometimes?


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 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences