(3log₇ 2 - log₇ 24) / (log₇ 3 + log₇ 9) =(log₇ 2³/<span> 24) / (log</span>₇<span> 3* 9) =
lg1/3 </span>lg27 lg1/3 lg7 <span>
= </span>(log₇1/3) / (log₇ 27 ) = ---------- : --------- = ----------- * --------- =
lg7 lg7 lg7 lg27
lg1/3
= ---------- = Log ₂₇ 1/3 = Log ₃³ 3⁻¹ =1/3 *(-1)Log₃ 3= -1/3
lg27
Первое, второе, четвертое. Насчет второго не уверен
<span> (sin 5п/4-cos3п/4)*tg7п/3=(sin(п+п/4)
– cos(п-п/4)
) * tg(2п+п/3)=
( – sin п/4 –( – cos п/4 ))*tg п/3= (cos п/4 – sin п/4)*tg <span>п/3 = (2^0.5/2
– 2^0.5/2)*3^0.5=0</span></span>