Explain how to write an equation when given a description of a mathematical problem or real-world scenario.

How do i make someone brainliest? (if you answer me, i might be able to make you brainliest! )

Aword processing program requires a 7- digit registration code made up of the digits 1,2,4,5,6,7 and 9 each number has to be used and no number can be used mor than once how many codes are possible

The volume of the a sphere whoes diameter is 18 cm is cubic cm . if it's diameter were reduced by half, it's volume would be of its original volume