x⁸ + x⁷ + 1 = x⁸ + x⁷ + x⁶ - x⁶ + 1 = (x⁸ + x⁷ + x⁶) - (x⁶ - 1) =
= x⁶(x² + x + 1) - ((x³)² - 1) = x⁶(x² + x + 1) - (x³ - 1)(x³ + 1) =
= x⁶(x² + x + 1) - (x - 1)(x² + x + 1)(x³ + 1) = (x² + x + 1)(x⁶ - x⁴ + x³ - x + 1)
Пешеход пройдёт 1/3 часть пути
(2a-3b)-(a-b)=2а-3b-a+b=a-2b
1) 5x^2+3x=0
D=9
x1=(-3+√9)/4=0
x2=(-3-√9)/4=-6/4=-1 1/2=-1.5
2) 2x^2-1.2x=0
D=1.44
x1=0
x2=1.2+√1.44=2.4