Solving systems of linear equations by graphing

The means and mean absolute deviations of the individual times of members on two 4x400-meter relay track teams are shown in the table below. means and mean absolute deviations of individual times of members of 4x400-meter relay track teams team a team b mean 59.32 s 59.1 s mean absolute deviation 1.5 s 245 what percent of team b's mean absolute deviation is the difference in the means? 9% 15% 25% 65%

If tan2a=cot(a+60), find the value of a, where 2a is an acute angle

Two years ago a man was six times as old as his daughter. in 18 years he will be twice as old as his daughter. determine their present ages.