.
Find the principle fourth root of -81, checking your answer by raising to the 4th power. If there are "no real roots," then type: NONE

Find the principle cube root of -27, checking your answer by cubing (raising to the 3rd power). If there are "no real roots," then type: NONE

Find the principle square root of 4/25. Give your answer as a fraction in simplest form (numerator, then "/", then denominator). If there are "no real roots," then type: NONE

answer: 25.4 units

step-by-step explanation: radius = 12.7 units

diameter = twice the radius

diameter = 12.7 x 2

= 25.4

reduce the friction between its moving parts

step-by-step explanation:

in fact, by reducing the friction between the moving parts of the machine, it is possible to reduce the energy wasted due to this friction; therefore, more input energy is converted into useful work, and this will improve the efficiency of the machine.

lo98765432wqasdfghjkloi87654567890

step-by-step explanation: