Add 1/3n + 2/3 and -1/6n + 1/6m

Someone explain what to do..

Both the red and blue line segments stretch from the center of the circle to a point on the circle. the length of the blue segment is 5. how long is the red line segment?

Players on the school soccer team are selling candles to raise money for an upcoming trip. each player has 24 candles to sell. if a player sells 4 candles a profit of$30 is made. if he sells 12 candles a profit of $70 is made

Credit card a offers an introductory apr of 3.4% for the first three months and standard apr of 15.7% thereafter,