4(2x²-4x+3)-3x(5-4x)=8x²-16x+12-15x+12x²=20x²-31x+12
=а^9•а^-10=а^-1=1/а,подставим 1:(1/4)=4
Sin²α+cos²α=1
sin²α=1-cos²α
sin²α=1-16/25
sin²α=9/25
/sinα/=3/5
α∈(π/2,π) : sinα=3/5
tgα=sinα/cosα, tgα=3/4
cos2α=cos²α-sin²α=16/25 - 9/25
cos2α=7/25
5^(x[x+3]) = 4/100
5^(x[x+3]) = 1/25
5^(x[x+3]) = 5^-2
x(x+3) = -2
x^2 + 3x + 2 = 0
D > 0
x = -2, x = -1
D = V 2*R*h8 = V 2*6400*h8^2 = (V 2*6400*h)^264 = 2 * 6400 *hh = (2 * 6400)/ 64 h = 5Hпод = 5 - 1.7 = 3.3 мкол = 330 / 25 = 13,75 ~ 14