Marcel is helping his two children, jacques and gilles, to balance on a seesaw so that they will be able to make it tilt back and forth without the heavier child, jacques, simply sinking to the ground. given that jacques, whose weight is w, is sitting at distance l to the left of the pivot, at what distance l1 should marcel place gilles, whose weight is w, to the right of the pivot to balance the seesaw?