Write an expression to represent a circle's area in terms of its diameter, d .

(d/2)^2 pi

Step-by-step explanation:

To find the area of a circle the formula is A=pi times radius sqaured. Since we do not have the radius we need to find it. The radius will always be half the diameter hence the (d/2). This will give us the radius, next is just to complete the area formula by squaring the radius and multiplying it by pi.  i hope this helps :)

let's cover over the formula of the vertex:

y = a(x – h)^2 + k

in this formula, (h,k) are the vertex, always remember that the positive or negative value of the vertex is based on the sign it has.

for example, if the vertex is -3,-6 then both the x and y value would have the positive sign attached to it and if it were a positive x and y value, then a negative sign would be attached to it.

with that being said, for our problem the x value is a positive one so we are looking for a number with a negative sign next to it, in this case the first and second choice.

however, for the first answer choice it isn't quite part of the formula so we know that the answer choice correctly displays the x value.

to confirm, we can see if the -1 fits correctly with the second answer choice, and as mentioned above a negative number will have a positive sign attached to it. so, for our problem we can see that -1 has been changed to +1, so we can confirm that the second answer choice is correct.

hence, our final answer is y=(x - 1)^2 + 1

125 yards

step-by-step explanation:

i take 75 plus 50.