Which line is perpendicular to y=2x-7

Combined megan and kelly worked 60 hours.kelly worked twice as many hours as megan.how many hours did they each worked?

Each cookie sells for $0.50 sam spent $90 on baking supplies and each cookie cost $0.25 to make how many cookies does sam need to sell before making a profit formula: sales> cost

The perimeter of a quarter circle is 14.28 miles. what is the quarter circle's radius?