Question

3a-(-3a-b)al cuadrado+ab

Answer 1

$3a-(-3a-b)^{2} +ab$

$3a - (9 a^{2} +6ab + b^{2} ) +ab$

$3a - 9 a^{2} -6ab -b^{2} +ab$

$3a - 9 a^{2} -5ab -b^{2}$