Knowing your takes the guesswork out of trying to drink the right amount of fluids during workouts. a. fluid preferences b. sweat rate c. carbohydrate level d. available drink options

I Believe is it B. the reason is simple because of common sense. You got to know how much you sweat to know how much to drink.

For 15 to 20, change the equation from y=mx+b into mx-y=-b
Example: 15) y=-5x+2 into -2=-5x-y or 2=5x+y
For 21-29, the numbers in the parenthesis are coordinates (x, y) so uh the equation y=mx+b plug in the m that is given and x and y and then solve for b to complete the equation
Ex: 21) (-8,3) m=2
Y=mx+b
3=2(3)+b
3=6+b
-3=b
So y=2x-3
Do the same to the others