Which expression is equivalent to 350−−√⋅22−−√?

If sec theta = 5/3 and the terminal point determined by theta is in quadrant 4, then

Expresa commuter train leaves downtown sation and travels at a average speed of 55 miles per hour towards the north side sation, which is 50miles away. thirty minutes later, express commuter train #7 leaves north side and travels at a average speed of 35miles per hour towards downtown sation. at the moment the two trains pass each other, how far(in miles) is train #12 from the downtown sation and how long(in minutes) has the #12 train been traveling

Cole says the distance between points (-5,0) and (0,-5)is 5 units. is he correct? explain why or why not.