a) 2sin245∘+7tg30∘⋅cos120∘=2⋅(22)2+7⋅33⋅cos(90∘+30∘)=
=2⋅42+7⋅33⋅(−sin30∘)=1+7⋅33⋅(−21)=1−673
b) 4(tg150∘−cos30∘):(sin120∘+tg60∘1)=
=4(tg(180∘−30∘)−23):(sin(90∘+30∘)+31)=
=4(−tg30∘−23):(cos30∘+31)=4(−33−23):(23+33)=
=4⋅(−23+3333+23)=4⋅(−1)=−4
c) (tg120∘−tg60∘)2−(tg150∘+tg60∘)2=
=(tg(180∘−60∘)−3)2−(tg(180∘−30∘)+3)2=
=(−tg60∘−3)2−(−tg30∘+3)2=(−3−3)2−(−33+3)2=
=(−23)2−(3−33)2=4⋅3−32−2⋅3⋅33+(33)2=
=12−(3−2+93)=12−131=1032
d) sin360∘+3sin2120∘⋅cos150∘−tg120∘=
=(23)3+3⋅(sin(90∘+30∘))2⋅cos(90∘+60∘)−tg(180∘−60∘)=
=833+3⋅(cos30∘)2⋅(−sin60∘)+tg60∘=833+3⋅(23)2⋅(−23)+3=
=833+3⋅43⋅(−23)+3=833−893+883=823=43
e) 33(tg60∘+3sin90∘)(2⋅sin120∘−cos90∘)+tg0∘=
=33(3+3⋅1)(2⋅sin(90∘+30∘)−0)+0=
=33⋅23⋅(2⋅cos30∘)=2⋅2⋅23=6
