Math P1 functions doubt

[arlery]

November 2009 V1, Q 10 (ii)

http://www.xtremepapers.me/CIE/Internat ... _qp_11.pdf

How can I find the inverse of g(x) ?

 

[ahmed t]

all u have to do is make x the subject of the formula as usual
cross multiply so it will become
y(x+3)=2x-1
then open the bracket so it will become
yx +3y =2x-1
rearranging
3y+1=2x-xy
taking x as the common factor on the RHS
3y+1=x(2-y)
dividing both sides by (2-y)
giving u a final anser of
3y+1/2-y=X
u may replace Y with X now