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.
The equation has the same solution as w / 3.9 = 3 is w+0.6=1.9
Given:
w / 3.9 = 3
cross multiply
w × 3 = 3.9
3w = 3.9
divide both sides by 3
w = 3.9 / 3
w = 1.3
<em>Check all that applies</em>
A. w+0.6=1.9
w = 1.9 - 0.6
w = 1.3
B. w-0.6 = 11.1
w = 11.1 + 0.6
w = 11.7
C. w+1.03=2.93
w = 2.93 - 1.03
w = 1.9
D. w-1.03=8.24
w = 8.24 + 1.03
w = 9.27
Therefore, the equation has the same solution as w / 3.9 = 3 is w+0.6=1.9
Learn more about equation:
brainly.com/question/2972832
Answer:
A, 120.
Step-by-step explanation:
x-15+75=180
x+60=180
x=120.
First you had to rewrite the problem with eighteen as the three times six is equal to eighteen.

Then you factor it out by the common term of six.

Final answer: 
Hope this helps!
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-Charlie
With what?!??!? Bvbheifnfnfjdjbe