6,051.2 rounded to the nearest thousand

How do i do this? i don’t understand

Which coefficient matrix represents a system of linear equations that has a unique solution ? options in photo*

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?