4-4. Can someone please tell me whether its B or C?
I'm leaning towards B but a friend said C.

Step-by-step explanation:

Choice B is correct. It’s given that the helicopter’s initial height is 40 feet above the ground and that when the helicopter’s altitude begins to increase, it increases at a rate of 21 feet per second. Therefore, the altitude gain t seconds after the helicopter begins rising is represented by the expression 21 t. Adding this expression to the helicopter’s initial height gives the helicopter’s altitude above the ground y, in feet, t seconds after the helicopter begins to gain altitude:  y equals, 40 plus 21 t.

450

step-by-step explanation:

you get texts and minutes, so why not

step-by-step explanation:

you can add the two numbers and divide the result by 2. or you can find the gap between the two numbers and add half of this to the smaller number.