Answer :
f(x) = y = 2x+1
1st replace x by y & y by x
x= 2y + 1 so : 2y +1 = x ; 2y = x-1 & y = (x-1)/2
1st replace x by y & y by x
x= 2y + 1 so : 2y +1 = x ; 2y = x-1 & y = (x-1)/2