Question

(a+2b)(3a+b)-(a+b)(a+2b)+(a+2b)²

Answer 1

Then keep expanding them and you'll get the answer.

{a(3a+2b)+2b(3a+2b)} - {a(a+2b)+b(a+2b)} + (a²+4b²+4ab)
They require more expansion, do it yourself. :)

Answer 2

soln of ur ques.......