Can someone help me please???

How do i put 3(x+7) in distributive property

Cal's go cart has a gas tank with the dimensions shown below. he uses a gas can that holds 11 gallon of gas, to fill the go cart tank. 11 gallon = 231 inches^3 how many full gas cans will it take to fill the go cart's gas tank?

Rewrite the expression in z to the n power. the expression i was given is: 1 over z to the negative 1 half power.