1) (1,6*10^-5)(4*10^2)
2)18-х^2=14
3) х^2+2=х+2
4) х(х+3)=4
5)х(х-4)=-3

1) (1,6*10⁻⁵)(4*10²) = 6,4*10²⁻⁵ = 6,4*10⁻³2) 18 - х² = 14     18 - 14 = х²         х² = 4         х = 2;  х = -23) x² + 2 = x + 2     x² - x = 0     x(x - 1) = 0     x = 0;   x = 14) x(x + 3) = 4     x² + 3x - 4 = 0     D = b²-4ac = 9+16 = 25     x₁ = (-b+√D)/2a = (-3+5)/2 = 1      x₂ = (-b-√D)/2a = (-3-5)/2 = -45) x(x - 4) = -3     x² - 4x + 3 = 0     D = b²-4ac = 16-12 = 4     x₁ = (-b+√D)/2a = (4+2)/2 = 3      x₂ = (-b-√D)/2a = (4-2)/2 = 1