Please help me i have no idea what im doing

If f(x) = 2x - 6 and g(x) = 3x + 9, find (f - g)(x). a. (f-g)(x) = x + 15 o o b. (f- g)(x) = -x - 15 o c. (f- g)(x) = 5x + 3 o d. (f- g)(x) = -x+3 submit

Apatient is to be given 35 milligrams of demerol every 4 hours. you have demerol 50 milligrams/milliliter in stock. how many milliliters should be given per dose?

You are standing next to a really big circular lake. you want to measure the diameter of the lake, but you don't want to have to swim across with a measuring tape! you decide to walk around the perimeter of the lake and measure its circumference, and find that it's 400\pi\text{ m}400? m. what is the diameter dd of the lake?