If A=30° and B=60°,show that sinc(A+B)= sinA . cos60°.sin 30°

Find the average speed of a rabbit that runs a distance of 22 m in a time of 1.8 s .

What is the greater volume 72 quarts or 23 gallons

Offering 30 if a plus b plus c equals 68 and ab plus bc plus ca equals 1121, where a, b, and c are all prime numbers, find the value of abc. the answer is 1978 but i need an explanation on how to get that.