What does it mean when a number has parentheses around it? Just like one whole number

The center of a circle represent by the equation (x+9)^2+(y-6)^2=10^2 (-9,6), (-6,9), (6,-9) ,(9,-6)

Two cyclists 84 miles apart start riding toward each other at the same. one cycles 2 times as fast as the other. if they meet 4 hours later, what is the speed (in mi/h) of the faster cyclist?

Adam used 1072.4 gallons of water over the course of 7 days. how much water did adam use, on average, each day?