Math Word Problems Demystified - A Self Teaching Guide

The equation is

W 1 L 1 þW 2 L 2 ¼w 1 l 1 þw 2 l 2

80 ð 8 Þþ 84 ð 4 Þ¼ 95 ð 8 Þþ 75 ðxÞ

640 þ 336 ¼ 760 þ 75 x

976 ¼ 760 þ 75 x

976 
 760 ¼ 760 
 760 þ 75 x

216 ¼ 75 x

216

75

¼

751 x

75

2 : 88 ¼x

Sam needs to sit 2.88 feet from the fulcrum.

EVALUATION: Check the equation:

W 1 L 1 þW 2 L 2 ¼w 1 l 1 þw 2 l 2

80 ð 8 Þþ 84 ð 4 Þ¼ 95 ð 8 Þþ 75 ð 2 : 88 Þ

640 þ 336 ¼ 760 þ 216

976 ¼ 976

Fig. 16-5.

LESSON 16 Solving Lever Problems 177