(x² + 3x) /8 - x / 2 = 0
(x² + 3x) /8 = x / 2
8x = 2( x² + 3x)
8x = 2x² + 6x
8x - 2x² - 6x = 0
- 2x² + 2x = 0
2x² - 2x = 0
D = b² - 4ac = (-2)² - 4 × 2 × 0 = 4 = 2²
x₁ = 2 + 2 / 4 = 4/4 = 1
x₂ = 2 - 2 / 4 = 0 / 4 = 0
<span>4,5х+1,25 = 37 1/4
4,5х=37,25-1,25
4,5х=36
х=36:4,5
х=8
</span>
<span>sin11x*cos3x-cos11x*sin3x=</span>√<span>3/2
sin(11x-3x)=</span>√3/2
sin8x=√3/2
![8x=(-1)^n* \pi /3+ \pi n, n\in Z\\x=(-1)^n* \pi /24+ \pi n/8, n\in Z](https://tex.z-dn.net/?f=8x%3D%28-1%29%5En%2A+%5Cpi+%2F3%2B+%5Cpi+n%2C+n%5Cin+Z%5C%5Cx%3D%28-1%29%5En%2A+%5Cpi+%2F24%2B+%5Cpi+n%2F8%2C+n%5Cin+Z)