Express 3x^2+18x-1 in the form a(x+b)^2 +c

3x^2+18x-1 Bracket out 3x^2+18x  Factorise by bringing out the common factor of 3 = 3(x^2+6x) Divide the x coefficient by 2  =  3(x^2+3x) And then remove the square on the x^2 variable and add a square to the outside of the bracket = 3(x+3)^2 Then subtract the square of the previously divided x coefficient .i.e. (3)^2        =   3((x+3)^2 - 9) - 1)  = 3(x+3)^2 -27 -1 = 3(x+3)^2 -28

CO
Answered by Chukwudi O. Maths tutor

13203 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

At what points does the line y = x +1 intersect the circle x^2 + y^2 + 18x + 20y + 81 = 0.


Differentiate the following equation, y = x^9 + 3x^2 + x^(-1)


Simplify (3x^2 + x -2)/(x^2 - 1)


Solve the following simultaneous equations. x^2+y^2=25. y-3x=13


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