0,4 * 4 3/8 - (1/4 * 1/4) = 1 11/16
1) 0,4 * 4 3/8 = 2/5 * 35/8 = 2/1 * 7/8 = 14/8
2) 1/4 * 1/4 = 1/16
3) 14/8 - 1/16 = 28/16 - 1/16 = 27/16 = 1 11/16
50+80=130 км/час скорость удаления автобуса и легк.машины 130*3=390км(на 390 км удалятся за 3 часа)
1) sin x = -1/2; x = (-1)^n*(-Π/6)+Π*n
2) cos(3x-Π/4) = √2/2
3x-Π/4=Π/4+2Π*k; x1=Π/6+2Π/3*k
3x-Π/4=-Π/4+2Π*n; x2=2Π/3*n
3) tg(2x/3)=1/√3
2x/3=Π/6+Π*k; x=Π/4+Π/2*k
4) ctg(x+Π/6)=1/3; x=-Π/6+arcctg(1/3)+Π*k
5) 2sin^2 x - 9cos x + 3 = 0
2 - 2cos^2 x - 9cos x + 3 = 0
2cos^2 x + 9cos x - 5 = 0
(2cos x - 1)(cos x + 5) = 0
cos x = -5; решений нет
cos x = 1/2; x = ±Π/3 + 2Π*k
6) (1 + cos x)(tg x - √3) = 0
cos x = -1; x1 = Π + 2Π*k
tg x = √3; x = Π/3 + Π*n
<span>2-10000020204500=-10000020204498</span>