(-х^2)^3 · x^7 / x^15 = -x^6 · x^7 / x^15 = -x^13/x^15; при х = -1/4 = 1/4^13 / 1/4^15 = 0.25^13 / 0.25^15 = 1 / 0.25^2 = 0.0625
