Find the value of x.
⇒ x + 2x + 3x = 180∘
⇒ 6x = 180∘
⇒ x = 30∘
If tan−1x+tan−1y=π4 where xy < 1, find the value of x+y+xy.
If x2+xy+x=12 and y2+xy+y=18 then find the value of x-y is