How to simplify an equation and remove the denominator in Maple?

Question

Say I have $$ f(x)=\frac{ax+b}{cx+d} $$ I wish to assgin $f(x)=1$ and simplify to have $$ ax+b-cx-d=0. $$ How may I do this in Maple? I tried

simplify(f=1,x)

but it didn't work.

Answer 1

Your question seems more about Maple programming than mathematics, and as such is more suitable for stackexchange.com than math.stackexchange.com in my opinion.

f := (a*x+b)/(c*x+d);           

                                  a x + b
                             f := -------
                                  c x + d

eq := f = 1;                    

                                 a x + b
                           eq := ------- = 1
                                 c x + d

eq - rhs(eq); # RHS becomes zero

                            a x + b
                            ------- - 1 = 0
                            c x + d

map( numer, % );                

                         a x - c x + b - d = 0

Or, more straightforwardly,

f := (a*x+b)/(c*x+d):

numer( f-1 ) = 0;               

                         a x - c x + b - d = 0