Question

2．某校初一年級(jí)到禮堂開(kāi)會(huì)，若每條長(zhǎng)凳坐5人，則少10條長(zhǎng)凳；若每條長(zhǎng)凳坐6人，則又多余2條長(zhǎng)凳．如果設(shè)學(xué)生數(shù)為x人，長(zhǎng)凳為y條，根據(jù)題意可列方程組（　�。�

• A． $\left\{\begin{array}{l}{x=5y+5×10}\\{x=6y-6×2}\end{array}\right.$
• B． $\left\{\begin{array}{l}{x=5y-5×10}\\{x=6y+6×2}\end{array}\right.$
• C． $\left\{\begin{array}{l}{x=5y-10}\\{x=6y+2}\end{array}\right.$
• D． $\left\{\begin{array}{l}{x=5y+10}\\{x=6y-2}\end{array}\right.$

Answer 1

分析 設(shè)學(xué)生數(shù)為x人，長(zhǎng)凳為y條，根據(jù)每條長(zhǎng)凳坐5人，則少10條長(zhǎng)凳；每條長(zhǎng)凳坐6人，則又多余2條長(zhǎng)凳，列方程組即可．

解答 解：設(shè)學(xué)生數(shù)為x人，長(zhǎng)凳為y條，
由題意得，$\left\{\begin{array}{l}{5（y+10）=x}\\{6（y-2）=x}\end{array}\right.$，
整理得：$\left\{\begin{array}{l}{x=5y+50}\\{x=6y-12}\end{array}\right.$．
故選A．

點(diǎn)評(píng) 本題考查了由實(shí)際問(wèn)題抽象出二元一次方程組，解答本題的關(guān)鍵是讀懂題意，設(shè)出未知數(shù)，找出合適的等量關(guān)系，列方程組．