According to the distributive property, 3(a + b) = a3a + b b) 3a + 3b c) 3 (b + a) d) a (3 + b)

3(a + b)

using distributive property would become

3a +3b

 Answer is B

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.