Posted by HELPP!!! on Thursday, January 10, 2013 at 10:07pm.
Whenever you have a statement such like yours,
"If y varies directly as x "
you can form the equation
y = kx , where k is a constant
sub in the given: y=3 , x=10 to find k
3 = k(10)
k = 3/10
so your equation is y = (3/10)x
then when y = 8
8 = (3/10)x
80 = 3x
x = 80/3
btw, if it has said" y varies inversely as x" your equation would have been
y = k(1/x), but you would follow the same steps of subbing in the given data to find k
Thank you so much that helps a lot!
welcome
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