Question

“今有木，不知長(zhǎng)短，引繩度之，余繩四尺五寸，屈繩量之，不足一尺，木長(zhǎng)幾何”
意思是：用一根繩子去量一根長(zhǎng)木，繩子還剩余4.5尺，將繩子對(duì)折再量長(zhǎng)木，長(zhǎng)木還剩余1尺，問(wèn)長(zhǎng)木長(zhǎng)多少尺？

Answer 1

分析：本題的等量關(guān)系是：繩長(zhǎng)-木長(zhǎng)=4.5；木長(zhǎng)-

1

2

繩長(zhǎng)=1，據(jù)此可列方程組求解．

解答：解：設(shè)繩長(zhǎng)x尺，長(zhǎng)木為y尺，
依題意得

x-y=4.5 y- 1 2 x=1

解得

x=11 y=6.5

．
答：長(zhǎng)木長(zhǎng)6.5尺．

點(diǎn)評(píng)：古代問(wèn)題中經(jīng)常有二元一次方程組問(wèn)題，關(guān)鍵是弄清題意，找準(zhǔn)等量關(guān)系，列對(duì)方程組，求準(zhǔn)解．