Answer:
C. 2
Step-by-step explanation:

hope it helps :)
19x2-9x2= 10x2
16x-13x= 3x
45-23= 22
(10x2+3x+22)
Answer:
7.0 m/s
Step-by-step explanation:
We can solve this using the 2 kinematic equations and you can use either:

So let's use the first one.
Vi = initial velocity
Vf = final velocity
a = acceleration due to gravity (constant 9.8m/s²)
t = time
The marble is dropped so this means that it is in free fall. The initial velocity is always 0m/s.
We are given then the following:
d = 2.5m
t = 0.71s
Vi = 0 m/s
a = 9.8m/s²
So we plug in the values we know and solve:

13 x 17n - 13 x 15
= 221n - 195