<span>3аа4 +3аа3-5а2а3 -5а2а=</span>6a2a7-10a4a3=-4a2a4
27^1/3*a^5/3*b^-2/3* a^1/3* b^11/3*1/2=3/2*a^(5/3+1/3)*b^(-2/3+11/3)=
= 3/2*a²b³
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b^1/4*b^-3/2* b^13/4=b^(1/4-3/2+13/4)=b²
<span>sin 19 + sin 17 + sin 15=(sin 19 + sin 15)+sin 17=2sin 17 *cos 2 +sin 17= sin 17(2cos 2+1) </span>