Represent the following sentence as an algebraic expression, where "a number" is the letter x. You do not need to simplify.
The product of 2 and the difference of a number and 3.

An airplane travels at an unknown elevation before it descends 3 miles to an elevation of 15 miles. find the elevation of the plane before its descen.

Plz hurry evaluate the expression a+b where a=8 and b=19

Frank has a devised a formula for his catering business that calculates the number of meatballs he needs to prepare. the formula is m=4a+2c, where c=number of children; m=number of meatballs; a=number of adults. how many meatballs are required for a party of 10 adults and 5 children?