If y varies directly as x and x=12 when y=10, find y when

spoons

New member
Joined
Apr 27, 2008
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If y varies directly as x and x=12 when y=10, find y when x=40.

How would I find slope and y-intercept (if any)?
 

skeeter

Senior Member
Joined
Dec 15, 2005
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y varies directly as x ...

the above statement translates to the equation y = kx, where k is a proportionality konstant.

find k with your given info ...

10 = k*12

k = 5/6

y = (5/6)x

now find y when x = 40
 

spoons

New member
Joined
Apr 27, 2008
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3
thanks skeeter. i thought that i would have to set up a slope-intercept equation for some reason.
 
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