S spoons New member Joined Apr 27, 2008 Messages 3 Apr 27, 2008 #1 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)?

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 Messages 2,396 Apr 27, 2008 #2 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

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

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