HELP PLZ 50 POINTS TAKE MY POINTS AND ILL TELL BRSINLY TO TAKE THEM AWAY FROM U AND BAN YOU FOR A 40 DAY SUSPENSION AND I WILL BAN YOU FROM MY ACCOUNT FOREVER. PLZ HELP

If tana tanb=k, show that(1+k)cos(a+b)=(1-k)cos(a-b)

An initial investment of $100 is now valued at $150. the annual interest rate is 5%, compounded continuously. the equation 100e0.05t = 150 represents the situation, where t is the number of years the money has been invested. about how long has the money been invested? use your calculator and round to the nearest whole number. years

What is 100,000 times 1/100,000, using the standard method of multiplication? write the answer as 10 to a power.