How do i find the solution to this using the substitution method? !

Agallon of apple juice cost $7 a pack of eight 4.23oz box of apple juice $2.39 which is a better deal

Apackage of orgainc strwberries costs $1.50 while there in season and $2.25 when not in season what the percent increase

The unpaid balance on a mastercard charge was $1,056.23. during the month, payments of $300 and $250 were made and charges of $425 and $274.16 were added. if the finance charge is 1.2% per month on the unpaid balance, find the new balance at the end of the month. $1,205.39 $1,218.06 $918.06 $1,768.06