How to find marginal profit function calculus?

While scuba diving, rajeev dove to a depth of 12.6 feet below the surface of the water and then descended another 8.7 feet. what expression can be used to find rajeev's new position? 12.6 – 8.7 –12.6 – 8.7 –12.6 – (–8.7) 12.6 – (–8.7)

Haley buys 9 pounds of apples for $3. how many pounds of apples can she buy for $1?

If (x-2) 2= 49, then x could be a. -9 b. -7 c.- 2 d. 5 e.9