1)90л - 100%
9л=х - 10%
2)90-9=81
3)81 : 2 = 40.5
4)49,5л в первом бидоне, 40,5 во втором бидоне.
1 + 14 = 15
14 + 1 = 15
15 - 1 = 14
15 - 14 = 1
2 + 13 = 15
13 + 2 = 15
15 - 2 = 13
15 - 13 = 2
также: 3+12=15, 4 + 11=15, 5 +10=15, 6 + 9=15, 7 + 8 = 15......
7 + 9 = 16
9 + 7 = 16
16 - 9 = 7
16 - 7 = 9
10 + 6 = 16
6 + 10 = 16
16 - 10 = 6
16 - 6 = 10
11 + 5 = 16
5 + 11 = 16
16 - 5 = 11
16 - 11 = 5
также: 4 +12 = 16, 3 + 13 = 16, 2 + 14 = 16, 1 + 15 = 16
А)1-sin0,7*cos0,7*tg0,7=1-sin0,7*cos0,7*sin0,7/cos0,7=1-1=0
Формула tga=sina/cosa
б)cos^4a+sin^2a*cos^2a=cos^4a+1
Формула cos^2a*sin^2a=1