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{0\cdot(-4)+2\cdot(-3)}{(-4)^2+2^2} + (\frac{-3\cdot(-4)-0\cdot2}{(-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]