Work out the percentage change to 2 decimal places when a price of £189 is decreased to £150.

The percentage change is -21%

Step-by-step explanation:

The percentage change can be expressed by the formula;

(new price -old price)/old price * 100%

New price = £150

old price = £189

Inputing these values in the formula, we have;

(150-189)/189 * 100%

-39/189 * 100%

= -20.63% and that is approximately -21%

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.