14-21х-6х-2=4+3х
-27х-12=4+3х
-30х=16
х=-1.875
1)arctg 0=0, arctg 1/√3=30, arctg√3=60, arctg1=45
0+60+30+45=135
2)arcctg 0= 90, arcctg1/√3=60, arcctg√3=30, arcctg1=45
90+60+30+45=215
3)arctg (-1)=-45, arctg(-√3)=-60 ,arctg(-1/√3)=-30, arcctg 0=90
-45+(-60)-(-30)-90=-45-60+30+90=15
7,4>7,399 ...,...................
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