123+123= what i ned help im half asleep

What is the difference between the predicted value and the actual value

Find an bif a = {3, 6, 9, 12) and b = {2, 4, 6, 8, 10).

Technicians have installed a center pivot, circular irrigator for a farm that covers 25 acres. a.) how long is the irrigation boom (in feet) from the center pivot to its farthest extent? b.) if the irrigation boom makes 4 full revolutions in a day, how many miles does the end of the boom travel in 5 days?