SOLUTION: A father and two children are going to play on a seesaw that is 10 ft long. The children will be at one end and the father alone at the other end. One child weighs 45lbs and the ot

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Question 1055410: A father and two children are going to play on a seesaw that is 10 ft long. The children will be at one end and the father alone at the other end. One child weighs 45lbs and the others is 70lbs. Their mother/father weighs 180lbs. How far should the pivot be FROM THE CHILDREN so that the seesaw can balance?
How do you solve using the formula W1x=w2(L-x) with a rounded answer?
Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
here's a good reference that might be helpful.
http://www.beaconlearningcenter.com/documents/1411_01.pdf

the basic formula is w1*d1 = w2*d1

the total distance is 10 feet.
the children will be at one end and the father will be at the other end.
the father weighs 180 pounds and the total weight of the children is 45 + 70 = 115 pounds.

the formula of w1*d1 = w2*d2 becomes 180 * d1 = 115 * d2

the total distance between them is 10 feet.

let x equal the distance from the father to the pivot.
let (10 - x) equal the distance from the children to the pivot.

you get d1 = x and d2 = (10 - x).

the formula becomes 180 * x = 115 * (10 - x)

simplify this formula to get 180 * x = 1150 - 115 * x

add 115 * x to both sides of the equation to get 180 * x + 115 * x = 1150 - 115 * x + 115 * x

combine like terms to get 295 * x = 1150

divide both sides by 295 to get x = 1150 / 295 = 3.898305085.

10 - x is therefore equal to 6.101694915.

the distance from the father to the pivot is 3.898305085 feet.

the distance from the children to the pivot is 6.101694915.

you were askedto find the distance from the children to the pivot.

round 6.101694915 to the nearest unit and it becomes 6 feet.

round 6.101694915 to the nearest tenth and it becomes 6.1 feet.

round 6.101694915 to the nearest hundredth and it becomes 6.10 feet.

normally, unless otherwise specified, you only round after all the calculations have been performed.