Mr. Olin bought 6 sketchbooks for the students in his art class. Each sketchbook was on sale for $3 off. If the sketchbooks cost $18 total before tax, what was the original price of each sketchbook?

ok so they buy sketch books for 3 dollars off so that means the original price was 3 more then 18 dollars so

3+18=21

so the original price was 21 dollars

Hope This Helps!!!

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.