3) 24-(3у+1)(4у-5)=(11-6у)(2у-1)+6
24-(12у²-15у+4у-5)=22у-11-12у²+6у+6
24-12у²+15у-4у+5=22у-11-12у²+6у+6
-12у²+15у-4у-22у+12у²-6у=-11+6-24-5
-17у=-34
у=2
4) (6у+2)(5-у)=47-(2у-3)(3у-1)
30у-6у²+10-2у=47-(6у²-2у-9у+3)
30у-6у²+10-2у=47-6у²+2у+9у-3
30у-6у²-2у+6у²-2у-9у=47-3-10
17у=34
у=2
Cos4x-3cos2x=1
2cos²2x-1-3cos2x-1=0
2cos²2x-3cos2x-2=0
D=9+16=25; √D=5
cos2x=(3+5) /4=2 - |t|≤1
cos2x=-1/2
2x=±2π/3+2πn, n € Z
x=±2π/6+πn, n € Z
7-3*(2^6)^1/6=7-3*2=7-6=1
(-1,5ab^3)0,5a^4b / (1/2a^3b^2)^3 =
<span> -0,5(7b-12a) - (8.4a - 14b)= при а = - 10, b = - 6
=-3,5b+6a-8,4a+14b=
=-11,9b+20b
-11,9* (-6)+20*(-10)=
=71.4-200=
=-128.6
</span>