Acredit card company offers a cash back program on transactions. for every transaction over $100, the customer gets $3 back. for every transaction $100 or less the customer gets $1 back. the customer made 18 transactions in all and the total number of dollars given back was $28.write and solve a system of equations to find the number of transactions of each type using the following let statements : x= transactions over 100 y= transactions under 100 ? x +? y = 28 -7x+y=32