Simplify the square root of -16 + the square root of -9

Solutions for 2x+7 less than or equal to 3x-5

Find the length of the normal and the angle it makes with the positive x-axis. (see pictured below)

Adolphin is swimming with her friend. the dolphin jumps to a height of 4.54.54, point, 5 meters above the surface of the water as her friend swims 9.89.89, point, 8 meters directly below her. what is the position of the dolphin's friend relative to the surface of the water? meters