What value of x would make 3x-9 equals to 39

16

Step-by-step explanation:

To solve the equation you must isolate the variable.

3x-9=39

So first, add 9 to both sides

3x-9+9=39+9

3x=48

Then divide both sides by 3

3x/3=48/3

x=16

he spend 5.1 minutes chatting with his friends.

step-by-step explanation:

2/5+1/2=9/10

6/1-9/10=5.1

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.