An 18-foot ladder leaned up against a wall forms an angle of 70 degrees with the ground. how high up the wall will the ladder reach?

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?

What’s -11-33k and factor each expression completely

Math i have no idea how to do a and b