What is the product of 713 and 82

Keith bought a soft drink for 4 dollars and 9 candy bars .he spent a total of 31 dollars .how much did each candy bar cost?

Can you me find the missing length. i attached an image.

Sam is a waiter at a local restaurant where he earns wages of $5 per hour sam figures that he also eams about $3 in tips for each person he serves sam works 6 hours on a particular day. if n represents the number of people sam serves that day, which of the following functions could sam use to figure ehis total earings for the do o a. en) = 30 o b. en) = 5n+ 18