Помогите ребят! 1) 3i(7-4i)-(-5-3i)^2 2)-3i/-4+2i 3) x^2+100=0 втыкаю чет :C

[latex]1),3i(7-4i)-(-5-3i)^2=21i+12-16-30i=-4-9i[/latex][latex]2), z= frac{-3i}{-4+2i}= frac{0cdot(-4)+2cdot(-3)}{(-4)^2+2^2} + (frac{-3cdot(-4)-0cdot2}{(-4)^2+2^2} )i= -frac{3}{10} + frac{3}{5}i [/latex][latex]x^2+100=0\ x^2=-100\ x^2=-10^2\ x=pm10i[/latex]