Question

$<var>(a+b)+(a+b)</var>$(a+b)+(a+b)

Answer 1

arrange the like terms-
=>(a+b) + (a+b) + (a+b)²                    {here (a+b)² = (a+b)(a+b)}
=>a + a + b + b + a² + b² + 2ab          {(a+b)² = a²+b²+2ab}
=>a² + b² + 2a + 2b + 2ab
=> a² + b² + 2(a + b + ab) ANS.

Answer 2

[a+b] + [a²+2ab+b²] +[a+b]
a+b+a²+2ab+b²+a+b
2a+2b+2ab+a²+b²
2[a+b]+[a+b]²
[a+b][2+a+b]