Solve the following equation: (3(x-6) - 81)/4x = 0

The first step is to realise that a trivial solution of x is x = 0, which can be determined from the '4x' denominator. Now zooming in on the numerator and expanding gives us '3x^2 - 18 - 81'. Looking at the coefficients a factor of 3 can be taken out, leaving us with 'x^2 - 6 - 27'.Thinking of numbers that multiply to -27 and add to -6, the 27 immediately highlights that these will be some combination of 9 and 3. It is now apparent that the solution to this problem is in the form of (x-9)(x+3), giving x = 9, -3 or 0

HP

Related Maths GCSE answers

All answers ▸

Solve x^(2) + 7x + 6 = 0.


How does Pythagoras Theorem work?


How do you factorise a quadratic equation?


ABCD is a rhombus on a graph. B(7,10). AC: y=7-4x. Find an equation for DB in the form tx+py+r=0 where t,p&r are integers.