Answer: The answer for this equation is -5.3
Step-by-step explanation: The question states that a dolphin is swimming with her friend. The dolphin jumps to a height of 4.5 meters above the surface of the water as her friend swims 9.8 meters directly below her.
The surface of the water is 0 and the dolphin jumped to a height of 4.5 meters above the surface of the water. Making 4.5 a positive, and her friend swam 9.8 meters directly below her making 9.8 a negative.
So the equation of this would be 4.5 + (-9.8) or 4.5 - 9.8