Arccos(cos37π/3)=arccos(cos(12π+π/3))=arccos(cosπ/3)=arccos(1/2)=π/3
Q^2=b5/b3=2,25
q=1,5
b4=b3*q=4*1,5=6
<span> x+(2x+1)^2=10-(5-2x)(2x+5)
x+4x</span>²+4x+1=10+4x²-25
5x=-16
x=-16/5
x=-3.2
1)ОЗ 15
15-6х+9=30х-10-5х
25х+5х=24+10
31х=34
х=34/31
х=1 3/31
2)0,72х-2=0,48х+0,12
0,72х-0,48х=2+0,12
0,24х=2,12
х=214/24
=53/6
х=8 5/6
3)ОЗ 21
21х-12х+18=+35-28х=0
-19х=-53
х=53/19
х=2 15/19
4)х(х-9)=0
х=0 и х=9
5)х²=9
х=-3 и х=3