i don't know where I went wrong

[xc630]

Hi I need help inthis problem. The answer is supposed to be 1/2 but I get 11/2

tan A= 4/3
tan B= -1/2

i have to find tan (A-B)

So i did

tanA- tan B/ 1+ (tanAtanB)

4/3 - (-1/2) / 1 + (4/3 x -1/2)

8/6 + 3/6 / 1 +(-4/6)

(11/6) / (2/6)

And I got 11/2

Wher did I go wrong? Thank you

 

[Daniel_Feldman]

The answer is 11/2. It's a mistake by the book/answer sheet.