Answer:
Lindsey got 70% on this assignment.
Step-by-step explanation:
21 divided by 30 equals 0.7 which is 70% in percent form.
Answer is B
-0.6- (-0.4)= -0.6+0.4= -0.2
Answer: 2145 ²
Step-by-step explanation:
Answer:
3.15 seconds is the answer.
<u>Explanation</u>
when the ball touches the ground, h =0
hence,
0=255-21t-16t²
16t²+21t-225=0
here a=16 ,b=21, c= -225

time cannot be negative, hence t = -4.46 can be avoided
The ball takes 3.15 seconds to hit the ground.