What is the estimate of 872 times 3

Express the following as a function of a single angle, cos(60) cos(-20) - sin(60) sin(-20)

If the measure of xyz is 81 what is the measure of yz

Igor stravinsky tires sells approximately 3,760,000 car tires and 1,200,000 truck tires each year. about 47,000,000 care tires and 26,000,00 truck tires are sold each year in the united states. what is stravinsky's market share in each of these two markets (cars and trucks)?