Questions on Algebra: Functions, Domain, NOT graphing answered by real tutors!

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Question 167607: This is another form of problem that I am having trouble with. I would appreciate any help you can give me.
d varies inversely as w and directly as the square of v. If d=40 when w=6 and v=2, find d when w=9 and v=4.
d=kv2
40=k(4)2
40=k(16)
40/16=k
5/2=k: This is another form of problem that I am having trouble with. I would appreciate any help you can give me.
d varies inversely as w and directly as the square of v. If d=40 when w=6 and v=2, find d when w=9 and v=4.
d=kv2
40=k(4)2
40=k(16)
40/16=k
5/2=k
Answer by ankor@dixie-net.com(4660) About Me  (Show Source):
You can put this solution on YOUR website!
d varies inversely as w and directly as the square of v.
This translates to:
d =(kv^2)/w
:
If d=40 when w=6 and v=2,
40 = (k*2^2)/6
Find k
(4k)/6 = 40
:
Multiply both sides by 6
4k = 6*40
4k = 240
k = 240/4
k = 60
;
The equation: d = (60v^2)/w


find d when w=9 and v=4.
d = (60(4^2))/9
d = (60(16))/9
d = 960/9
d = 1062/3