SOLUTION: Please help! Two boys weighing 140 and 105lb, respectively, balance each other on a see-saw sitting 7 ft. apart. What is the distance of each from the pivot point? Thank You

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Question 74219: Please help!
Two boys weighing 140 and 105lb, respectively, balance each other on a see-saw sitting 7 ft. apart. What is the distance of each from the pivot point?
Thank You!
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Let x=distance from 140 lb boy and y=distance from 105 lb boy
140%2Fx=105%2FySet up a ratio between the distances and the weights
140y=105xMultiply both sides by xy to get rid of the fraction
x%2By=7Here's the sum of the distances
y=7-xSolve for y
140%287-x%29=105xplug this into x and solve
980-140x=105x
980=105x%2B140x
980=245x
980%2F245=x
x=4
So the 140 pound boy is 4 ft away from the pivot.
y=7-x
y=7-4
y=3
So the 105 pound boy is 3 ft away.