Store a charges $1,200 for repairs with a 6 percent sales tax. store b charges $1,350 with a 7 percent sales tax. explain how you would determine the amount of money saved by using store a instead of store b?

We know from the question that Store A charges $1200 for repairs and 6% as sales tax.
Then
Amount of sales tax charged by Store A = (6/100) * 1200
                                                                 = 6 * 12
                                                                 = 72 dollars
Then the total amount charged by Store A = ( 1200 + 72) dollars
                                                                   = 1272 dollars
Now coming to Store B. It charges $1350 for repairs and 7% of sales tax.
Amount of sales tax charged by Store B = (7/100) * 1350
                                                                 = 945/10
                                                                 = 94.5 dollars
Then the total amount charged by Store B = ( 1350 + 94.5) dollars
                                                                     = 1444.5 dollars
Amount of money saved by choosing Store A instead of Store B = (1444.5 - 1272) dollars
                                                                                                       = 172.5 dollars
So $172.5 is saved by choosing Store A over Store B.