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

Evan has a summer job to pick berries on a farm. He earns $2.00 every 15 minutes that he picks strawberries. He earns $2.40 for every 15 minuets that he picks blueberries. He picked strawberries for an hour and blueberries for 45 minuets.

if los angeles county wants to know what percent of its citizens have children who are in school readiness support, which method will be best to gather the information and why

Write the value of the 8 in this number 0.287

If 35 student are in student council, and 60% are boys. How many girls are in student council?

Use t = 3 and t = 7 to determine if 6t + 12 and 6 (t + 2) are equivalent. Which statements are true? Check all that apply.

What is the difference between - 4x - 6 and 2x + 4? Show work.

Solve the quadratic equation by factoring. check your solutions in the original equation. (enter your answers as a comma-separated list.) 2x2 = 19x + 33

A culture started with 3000 bacteria. After 4 hours, it grew to 3,600 bacteria. Predict how many bacteria will be present after 10 hours. Round your answer to the nearest whole number.

Find the number of terms in this polynomial. 9p2 + 3p - 2

What is the simplified form of the ninth root of x times the ninth root of x times the ninth root of x times the ninth root of x