How come this value of tan(A+B) is given Please explain - Maths - Some Applications of Trigonometry

Question

How come this value of tan(A+B) is given? Please explain

Ritesh Kumar · Accepted Answer

Dear student,
<img alt="" src=
"https://s3mn%20mnimgs%20com/img/shared/content_ck_images/ck_5f9a1f34902b0%20png"
style="width: 602px; height: 803px;">
Regards

How come this value of tan(A+B) is given?...Please explain.