Solve (72x^3 - 18x)/(12x^2 - 6x) = 0 for x.

So first you need to recognise that you are able to take 2x out of both the numerator and denominator of the fraction:(72x3 - 18x)/(12x2 - 6x) = 0 ---> (2x (36x2 - 9))/ (2x (6x - 3)) = 0 , the 2x's cancel and we are left with (36x2 - 9)/ (6x - 3)= 0 , from here it is necessary to identify that the numerator can be factorised by the difference of two squares: (6x - 3)(6x + 3)/ (6x - 3)= 0 , the (6x-3) brackets cancel and we are left with the simple equation, 6x+3 = 0, which is solved for x to be, x = -1/2.

Answered by William R. Maths tutor

2213 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Solve the follow simultaneous equation:4x + y= 4 and 2x + y= 8


Write 870,000,000 in standard form


Perimeter of isoceles triangle is 24cm. Sides 'x' = x + 3, side 'y' = x + 2, calculate the area


Factorise the expression: 2x^2 + 17x + 21


We're here to help

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