The circumference of an ellipse is approximated by C = 27v ?? where 2a and 26 are the lengths of the axes of the ellipse. Which equation is the result of solving the formula of the circumference for b?

Which system of linear inequalities is represented by the graph? + l tv x-3y > 6 and y > 2x o x + 3y > 6 and y o x-3y > 6 and y> 2x o x + 3y > 6 and y > 2x + 4 la +

In triangle △abc, ∠abc=90°, bh is an altitude. find the missing lengths. ah=4 and hc=1, find bh.

At the beginning of 1974/75,2 years a man invested #2000 in a bank at 12.5% compound interest, if it degree #650 at the end of each two years to pay his son's school fees, after payment of interest to pay his son's school fees, how much did he have left at the beginning of the 1978/79 school year?