Stacy owes 13.65 for text messging in the month of September if her text messaging plan cost 12 for the first 300 messages and 5c for each text message how many text messages did she send that month

If cos(2x) = tan^2(y), show that cos(2y) = tan^2(x).

Each person in an it department of 25 people works on at least one of 3 major projects: system security, program implementation, platform development. 10 people work on system security, 13 work on program implementation, and 12 work on platform development. 4 people work on system security and platform development, 5 people work on program implementation and platform development, and 2 people work on all three projects. how many people work on system security and program implementation?

The volume of the a sphere whoes diameter is 18 cm is cubic cm . if it's diameter were reduced by half, it's volume would be of its original volume