When you do a -90 degree rotation, what is the rule ie. a 180 degree rotation (x, y) -> (-x,-y)

Sal is tiling his entryway. the floor plan is drawn on a unit grid. each unit length represents 1 foot. tile costs $1.35 per square foot. how much will sal pay to tile his entryway? round your answer to the nearest cent.

Liam's parents are driving three times as fast as liam is biking, but they left later than he did. if his parents caught up with him two hours after he left, how much later than liam did they leave?

The conversion factor relating feet to meters is 1 ft=0.305 m. keep in mind that when using conversion factors, you want to make sure that like units cancel leaving you with the units you need. you have been told that a certain house is 164 m2 in area. how much is this in square feet?