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

Answer all these, i need it a lot 1. What is the value of y in the equation 2 (3y + 4 + 2) = 196 - 16 y= 2. What is the value of a in the equation a = 2 + 3a + 8 a= 3. How many solutions does the equation 4x + 8 = - 2 - 2 + 5x have solutions=

14 divied by 3/8 equals

a parallelogram's base is twice its height. If the parallelogram has an area of 32 square feet, what are the lengths of the base and height?

A Type II error is defined as which of the following? A. rejecting a false null hypothesis B. rejecting a true null hypothesis C. failing to reject a false null hypothesis D. failing to reject a true null hypothesis

How do you answer 64 divided by 2.56

Change the following numbers into percent 0.05

Calculate the discriminant: 5x² + 2x - 2 = 0

The Taco Shop sold 198 lunches Friday. This number is 3 more than 3 times the number they sold Monday. Let n represent the number of lunches sold Monday.

Susan received a $90 gift card for a coffee store she used it buying some coffee that cost $8.66 per pound after buying the coffee she had $64.02 left on a card how many pounds of coffee does she buy?

How many edges does a 3D pentagon have