<span>a^2+(3a-b)^2=a^2+9a^2-6ab+b^2=10a^2-6ab+b^2</span>
Если 5x^2 тогда =>
x(5x+20)=0
5x+20=0 и х=0
5x=-20
Ответ: x=-4 и х=0
Sin2x + 1 = Cosx + 2Sinx
Sin2x - 2Sinx + 1 - Cosx = 0
(2SinxCosx - 2Sinx) + (1 - Cosx) = 0
2Sinx(Cosx - 1) - (Cosx - 1) = 0
(Cosx - 1)(2Sinx - 1) = 0