y -x =2 and y + x= -2 ,Then ( x+y)(x-y)=?

COLLEGE BOARD Test 9 Math Section 3 #13

Could you suggest a shortcut or fast way to solve this? All the answers are written in vertex form, so we can quickly eliminate two of them, as the coordinates of the vertex, as indicated by the graph provided, must be (3,1). That leaves choices A and C. Is there a quick way to solve from there without plugging in values from the graph?

The call signs of radio and television stations in the United States generally begin with the letter W east of the Mississippi River and the letter K west of the Mississippi. Repetition of letters is allowed. How many different call signs are possible if each station uses a W or K followed by 3 letters?

O.M 0.N5

24. M and N represent digits in the two decimals

listed above. One of the decimals is equivalent

to 1/4 and the other is equivalent to 1/2. What

is the sum of M and N?

(A) 2

(B) 3

(C) 5

(D) 6

(E) 7

Renting video games from The Video Vendor costs

$6 per game with no annual membership fee. Renting

video games from The Game Garage costs $3 per

game, but a customer must pay an additional $60 for

an annual membership. If n represents the number of

video games a customer rents in a year, which of the

following gives all values of n for which it costs less

to rent from The Game Garage than from The Video

Vendor?

at 7am a sewage treatment tank contains 3000000 gallons of water. starting at 7am, x gallons per minute flow into the tank, and y gallons per minute flow out of the tank. no water enters or leaves the tank otherwise. which of the following functions f models the number of gallons of water in the sewage treatment plant at 8am?

In the equation below, the angle measures are in radians and is a constant.

𝑠𝑖𝑛(𝜋/8)=𝑐𝑜𝑠(𝜋/𝑎)

Which of the following could be the value of ?