<em>Всего 5 частей (2+3=5);</em>
<em>Одна часть равна 71 (355:5=71);</em>
<em>Тогда части будут <u>142</u> (71*2=142) и <u>213</u> (71*3=213).</em>
cos (α - π/2) = cos (-(-α +π/2) = cos (π/2-α)=sinα
X2-3x+5-4x2+2x+8=2-x-3x2
x2-4x2+3x2-3x+2x+x=2-5-8
x=-11
7х² + 8х + 1 = 0
D = 64 - 28 = 36
x1 = (-8 + 6)/14 = -2/14= -1/7
x2 = (-8 - 6)/14 = -14/14 = -1
Ответ: х = -1/7; 1.