State whether each pair of terms are like terms. (so yes or no)
7. 4xy and 3xy
8. 2s2 and 5s
9. -10a and -10b

Last month, leonhard euler's watch kiosk at the mall had total sales of $9,489. merchandise totaling $225 was returned. the goods that were sold cost leonhard euler's $5,481. operating expenses for the moth were $992. what was the gross profit on sales?