Simplify n+n+n+n?

How do I do this? Calculate the number of protons and the number of neutrons for each of the below

Round cake pan that is 2 inches deep and has 7 inch diameter what is the volume

180=112+9x+5. Whats the value of X and why?

Write a fraction that is a multiple of 4/5

Sara has 10 more freckles than Tim. Tim has 1 less feckle than Hank. Hank has 65 freckles. How many freckles does Sara have?

There are20 keys on a keychain. One of the keys starts a car. If a key is randomly chosen what is the probability that it starts the car A) 5% B) 25% C) 20% D) 15%

Best way to study math

Jak się oblicza procenty

The cube of the difference of 40 and a number

Camren has a clear container in the shape of a cube. Each edge is 9 centimeters long he found the volume of the container in cubic centimeters by multiplying the edge length by itself 3 times.