912-54950:a=610-483
912-54950 :a=127
54950:a=912-127
54950:a=785
a=54950:785
a=70
(912-54950:70)+483=610
3, 4/5 * 4, 4/5 = 456/5 = 91, 1/5
<span>1) sin(п-5а) +sin(-a) / cos3a * sin4a=sin(5a)-sina/cos3a*sin4a=</span>2sin2acos3a/cos3asin4a=
=2sin2a/2cos2asin2a=1/cos2a
1/cos120=1/cos(90+30)=-1/sin30=-2
406099, 743679, 436999, 70500