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А) 100а<span>²-20а+1=(100*100)а-20а+1=10000а-20а+1=9980а+1
</span><span>б)81х²-25у²=(81*81)х-(25*25)у=6561х-625у
</span><span>в)27х³-125у³=(27*27*27)х-(125*125*125)у=19683х-1953125у
</span>г)х⁴-х³-х+1=1х⁴-1х³-1х+1=(1*1*1*1)х-(1*1*1)х-1х+1=1х-1х-1х+1=-1х+1
вроде так, но я не уверен)
<span>lg(3x² + 7) - lg(3x-2) = 1
3x-2>0
x>2/3
lg(3x^2+7)/(3x-2)=lg10
3x^2+7=30x-20
3x^2-30+27=0
x^2-10x+9=0
(x-1)(x-9)=0
x=1
x=9</span>
arcsin(-корень из 3 на 2)=-П/3
2 5/8-2 5/14*2/3 2 5/8-33/14*2/3 2 5/8- 11/7
---------------------------------- = ------------------------------ = -------------------------- =
(3 1/12+4 375/1000):19 8/9 (3 1/12+4 3/8):19 8/9 (3 2/24+4 9/24):19 8/9
2 5/8 - 1 4/7 2 35/56 - 1 32/56 1 3/56 1 3/56
---------------------- = ------------------------- = ----------------- = ---------- =
7 11/24 : 19 8/9 179/24 : 179/9 179/24*9/179 3/8
=59/56 : 3/8 = 59/56*8/3=59/21=2 17/21