1.學(xué)校文具店里面又鋼筆和鉛筆共28盒,共計(jì)300支,鋼筆每盒10支,鉛筆每盒12支。請(qǐng)問(wèn):兩種筆各有幾盒?
用一元一次方程:解:設(shè)有鋼筆x盒,鉛筆(28-x)盒。鋼筆有:10x+12(28-x)=30010x+336-12x=300-2x =-36x =18鉛筆有:28-18=10(盒)用一元一次方程:解:設(shè)有鋼筆x盒,鉛筆(28-x)盒。鋼筆有:10x+12(28-x)=30010x+336-12x=300-2x =-36x =18鉛筆有:28-18=10...





