Question

Помогите пожалуйста со 2-ым, дам 25 баллов

Answer 1

$\displaystyle\bf\\-\Big(x^{2} \cdot 2y^{3}+(3xy)^{2} \Big) +\Big(-(-2x)^{2} \cdot y^{3}-2^{2} x^{2} \cdot 3y^{2}\Big)=\\\\\\=-\Big(2x^{2} y^{3} +9x^{2} y^{2}\Big) +\Big(-4x^{2} y^{3} -12x^{2} y^{2} \Big)=\\\\\\=-2x^{2} y^{3} -9x^{2} y^{2} -4x^{2} y^{3}-12x^{2} y^{2} =-6x^{2} y^{3} -21x^{2} y^{2}$