In this question, the speed of the dolphin is already given, but the unit is different. The speed of the dolphin is given as 40 miles per hour and it has to be converted to feet per hour.
We already know that 1 mile = 5280 feet
Then
40 mile = 5280 * 40 feet
= 211200 feet
So the speed in feet per hour will be 211200 feet per hour. I hope the procedure is clear enough for you to understand. You can always use this method for solving similar problems without requiring any help from outside.
200% bc it went up 2x as much as it cost before
Given that the point B is (1,1) is rotate 90° counterclockwise around the origin.
We need to determine the coordinates of the resulting point B'.
<u>Coordinates of the point B':</u>
The general rule to rotate the point 90° counterclockwise around the origin is given by

The new coordinate can be determined by interchanging the coordinates of x and y and changing the sign of y.
Now, we shall determine the coordinates of the point B' by substituting (1,1) in the general rule.
Thus, we have;
Coordinates of B' = 
Thus, the coordinates of the resulting point B' is (-1,1)