Please help me this question

  (b) Commutative Property of Rational Numbers

Step-by-step explanation:

In your equation, the terms on the left side have been reversed on the right side. This is an instance of use of the commutative property of addition. The property is a property of addition, and applies to any quantities that are added together, rational numbers or any other kind.

The closest appropriate choice is ...

  Commutative Property of Rational Numbers

The associative property applies to grouping of terms in a sum or product.

The distributive property applies to a property of multiplication over addition.

The additive inverse property says the sum of a number and its additive inverse is zero.

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.