Which equation has a constant proportionality equal to 1/2

Is the power produced directly proportional to the wind speed, give reasons for your answer?

Give the functions f(x) = |x + 2| - 3, what is the domain? a,b,c, or d all real numbers x > 2 x < -2 all real numbers and x cannot equal to 2

The difference of two numbers is 40. find the numbers if 0.3 parts of one number is equal to 37.5% of the other one.