Simplify : 3ab × (a+ b)-1 × (a-1 + b-1)

$\frac{1}{(a+b)}$ 1 (a + b) 3

3

3ab × (a+ b)-1 × (a-1 + b-1) Put the value of a and b = 1 = 3(1) × (1+ 1)-1 × (1-1 + 1-1) = 3 × \(\frac{1}{2}\) × 2 = 3