Y=2/5 * x^5 - 1/3*x^3 + x^1/7
y'=2x^4 - x^2 + 1/(7x^6/7)
1) Умножаем на 25
x^3 - 625x = x(x^2 - 625) = x(x - 25)(x + 25) = 0
x1 = -25; x2 = 0; x3 = 25
2) x^2 = 25/64
x1 = -5/8; x2 = 5/8
3) Умножаем на 9
4x^3 - 144x = 4x(x^2 - 36) = 4x(x - 6)(x + 6) = 0
x1 = -6; x2 = 0; x3 = 6
4а^2-12ab+9b^2/(15b-10a)=(2a-3b)^2/(15b-10a)=(2a-3b)^2/-5(2a-3b)=2a-3b/-5