Write the number four hundred thirty-eight million, eight hundred thousand is standard form

438,800,000

Step-by-step explanation:

The number 438 million comes first, so put 438 and then a comma.

The number 800 thousand is next, so put 800 and then a comma.

There is no number for the hundreds, tens, and ones place, so put 000 with no comma after, like this.

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.

x is greater than 5

step-by-step explanation:

2x+7 is greater than 17

    -7                           -7

2x is greater than 10

divide by 2 each side

x is greater than 5