If x is fish, y is octopi, and z is crabs, then you would have to know the numbers.
Then your answer would be c. 30x+80y-15z.
Because x=+30, y=+80, and z=-15.
I hope that helps. If you need any further help on this problem just ask.
H=0
Therefore:
144t-16t²=0
t (144-16t)=0
We have two equations:
1)
t=0 (when the ball is released)
2)
144-16t=0
-16t=-144
t=-144 / -16=9 (this is the time )
Answer: the ball hit the ground in 9 s.
Are you sure you didn’t miss anything while writing the question?
Cause we have nothing to go off. Everybody types differently so there is no way for us to say how long he typed for, unless we were given aprox how many words he wrote in a minute or something