Can some explain plain how to do part d. i understand all but part d. i know that you take 3.14 x 10 to the power of 2. which gives me 78.5. but this is divider by 4 and don’t understand how they got the 4. explain

Another type of subtraction equation is 16-b=7. explain how you would sole this equation then solve it.

Pyramid shown has a square base that is 18 inches on each side has a surface area of 164 square inches what is the slant height

Sam is a waiter at a local restaurant where he earns wages of $5 per hour sam figures that he also eams about $3 in tips for each person he serves sam works 6 hours on a particular day. if n represents the number of people sam serves that day, which of the following functions could sam use to figure ehis total earings for the do o a. en) = 30 o b. en) = 5n+ 18