Answer: C.) 1.12 seconds
Step-by-step explanation:
Hi, to answer this question we have to substitute h=0 (when the rock hits the ground the height above it is 0) in the equation given:
h (t) = –16t2 + 20
Solving for t (time)
0= –16t2 + 20
16t2=20
t2=20/16
t=√1.25 =1.12 seconds (option C)
Feel free to ask for more if needed or if you did not understand something.
Answer:
I believe the answer is D
-3x + 7x = -12
You need to add like terms.
4x = -12
Then, you need to divide both side by 4.
x = -3
So the answer is:
A) x = -3
90 for the first one
120 for the second one
