Действия:
1)700:2=350(ц)с 1-ого поля
2)350*7=2450(ц)
Ответ:2450центнеров
Элементарно Вацен
2sin(2x/3) ≤ -1
sin(2x/3) ≤ -1/2
4π/3 + 2πn ≤ 2x/3 ≤ 5π/3 + 2πn, n∈Z |*3/2
2π+2πn ≤ x ≤ 2,5π+2πn, n∈Z
[2π+2πn ; 2,5π+2πn] , n∈Z
2cos(3π-x/4)+3sin(π/2-x/4)<0
-2cos x/4 + 3cos x/4 <0
cos x/4 <0
π/2 + 2πn < x/4 < 3π/2 + 2πn, n∈Z |*4
2π+4πn < x < 3π + 4πn, n∈Z
(2π+4πn; 3π + 4πn), n∈Z
( 19/7 - 7/7 ) - (-7/3 - 18/4) = 12/7 + 41/6 = 359/42