What linear system of equations does the matrix represent? [-3 5 | 15] [2 3 | -10] a. -3x=2 5x=3 15x=-10 b. -3y=2 5y=3 15y=-10 c. -3x+5y=15 2x+3y=-10 d. -3x+5y=-10 2x+3y=15
Starting at home, emily traveled uphill to the hardware store for 606060 minutes at just 666 mph. she then traveled back home along the same path downhill at a speed of 121212 mph. what is her average speed for the entire trip from home to the hardware store and back?