Odpowiedź:
[tex]a)\ \ -(3y+7x)+(6x-9)=-3y-7x+6x-9=-3y-x-9\\\\\\b)\ \ (x^2+7x+1)-(4x+x^2)=x^2+7x+1-4x-x^2=3x+1\\\\\\c)\ \ 3y^2(-6y-3)-2y(y^2-6y-4)=-18y^3-9y^2-2y^3+12y^2+8y=\\\\=-20y^3+3y^2+8y\\\\\\d)\ \ \not4^2*\frac{3z+9}{\not6_{3}}+\frac{15z-10}{5}=2(z+3)+3z-2=2z+6+3z-2=5z+4[/tex]
