<span>sinx+sin5x+sin9x=0</span>
<span>2sin5xcos4x+sin5x=0</span>
<span>sin5x(1+2sin4x)=0</span>
<span>sin5x=0</span>
<span>x=пк/5</span>
<span>2sin4x=-1</span>
<span>sin4x=-0,5</span>
<span>x=-п/24+пк/4</span>
1-1
2-4
3-(-4а^5б^4с)
4-1
5-2м/3нм
6-А-4
Б-3
В-1
1) (3m² - m) + (2m - 3) - (m² - 3) =3m² - m + 2m - 3 - m² + 3 = 2m²+ m
2) -2mn(m² - 4mn + n²) =-2m³n + 8m²n² - 2mn³