а)
-1/4 + (-1/4)² + (-1/4)³ = -1/4 + 1/16 - 1/64 = -16/64 + 4/64 - 1/64 = -13/64,
-1/3 - (-1/3)² - (-1/3)³ = -1/3 - 1/9 + 1/27 = -9/27 - 3/27 + 1/27 = -11/27,
⇒⇒⇒⇒ -13/64 больше -11/27;