i need help with these two problems?

Question

1)y varies inversely as the square of x, and y=5 when x=3, what is y when x=3?
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2)y varies directly as the square of x, and y=125.when x=5 what is y when x=4?

Answer 1

i think yu ve made a mistake with the first question...in both the questions you make an equationand find the value of the consatant...
for eg,y=k/(x^2)....we ve to find k.
put x=3 y=5(these r d given conditions)
then we have,5=k/9
which gives k=45.
now if x=4(say)...y=45/16 and so...
similarly we can solve the second question
try it urself...best of luck!!

Answer 2

1) If y=5 when x=3, then y=5 when x=3!
2) If x=4, then y=100.

Answer 3

1) You have not asked the question correctly or y is 5 as the x=3, same as you described

2) You have wirtten square but it is cube and I think that y is 64 when x = 4.

Answer 4

y=k/x^2
x^2y=k
substituting 9*5=k
=>k=45
therefore the variation is x^2y=45

2.y=kx^2
substituting
125=k*25
so k=5
sothe variation is y=5x^2
when x=4
y=5*4^2
=80