Can y’all me with 7 - 12 showing work. will be giving brainliest: )) and for 13 and 14 i need too : )) :

Item 8 an account earns simple interest. $700 at 8% for 6 years a. find the interest earned. $ b. find the balance of the account. $

The number of revolutions of two pulleys is inversely proportional to their diameters. if a 24-inch diameter pulley making 400 revolutions per minute is belted to an 8-inch diameter pulley, find the number of revolutions per minute of the smaller pulley.

Which is the completely factored from of xy^3-x^3y