Prove cos (x+y) + cos (x-y) = 2cosxcosy

Annie has $1,400 in the bank. she takes out $700 for a new computer and then withdraws $120 each week for groceries. how many weeks can she withdraw grocery money?

Find the solution set of the inequality 8x-8

Expand the following 1/5 (10x-25)

1) y = 5x + 8 Does the equation represent a direct variation? What is the constant of variation? k = 2) x = 3y + 1 Does the equation represent a direct variation? What is the constant of variation? k =

Compare 600,000+20,000+3,000+900+10+1 to six hundred ninety two thousand, two hundred eighty six

Johny had 6 apples and he ate 6and lost five how much does he have now

The owners of a motel in Florida have noticed that in the long run, about 40% of the people who stop and inquire about a room for the night actually rent a room.

What is the hardest part / subject in math?

The graph shows a line joining two complex numbers. What are the two complex numbers?

Translate the sentence into an equation. Five more than the quotient of a number and 8 is 2. Use the variable for the unknown number.