(2/7+3/14)(-7,5+13,5)=(4/14+3/14)*6=(7/14)*6=(1/2)*6=3
Х-3·х+1=1х-3х+1=(1-3)х+1=-2х+1.
X² + 9 = 0
a = 1; b = 0; c = 9
D = b² - 4ac = 0 - 4·9 = -36 =
x₁ = (-b + √D)/2 = (0 + √(-36)/2 = √(-36)/2 = 6√(-1)/2 = 3i
x₂ = (-b - √D)/2 = (0 - √(-36)/2 = -√(-36)/2 = -6√(-1)/2 = -3i
Ответ: x = -3i; 3i.