-48+8x-12x+2x²+24x-4x²+6x²-x³-50-120+60+15x+120-20x+40-20x=
=-x³+4x²-5x+2
5у - у2 = 1- у2 + 4у +4;
5у - у2 - 1 + у2 - 4у - 4 = 0;
у - 5 = 0;
у =5
{3(-4-4у)-2у=16
{х=-4-4у
-12-12у-2у=16
-14у=28
у=-2
х=-4-4(-2)=-4+8=4
2cos+√3=0
2cos=-√3
cos=-√3/2
cos=+- arccos-√3/2+2πn n E Z
cos=+-5π/6+2πn n E Z
+-5π/6