3.07 × 10^-4 written in standard form

here are the choices

a. 0.00307

b. 0.000307

c. 30,700

d. 300,700

I believe the answer is B

Step-by-step explanation:

when you multiply 10x-4 to 3.07  it brings the answer back 4 times so the 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.

45

step-by-step explanation:

to find a percentage, add a decimal in front and multiply it by the other number.

.25 times 180= 45