At a new year's eve party, each person in the room kissed every other person in the room once. if by the end of the night there's been 190 kisses how many people were in the room?

Write a function for a rotation 90 degrees counter clockwise about the origin, point 0

Given the system of equations presented here: 2x + 4y = 14 4x + y = 20 which of the following actions creates an equivalent system such that, when combined with the other equation, one of the variables is eliminated? multiply the second equation by â’4 to get â’16x â’ 4y = â’80 multiply the second equation by â’1 to get â’4x â’ y = â’20 multiply the first equation by 2 to get 4x + 8y = 28 multiply the first equation by â’1 to get â’2x â’ 4y = â’14

Two trains leave stations 546 miles apart at the same time and travel toward each other. one train travels at 95 miles per hour while the other travels at 115 miles per hour l. how long will it take for the two trains to meet