数学题:化肥厂计划用15天生产化肥4500吨，钱5天平均每天生产340吨，后又提高了产量，结果提前3天就完了工，后几天平均每天生产化肥多少吨？（用方程解）

数学题解答：设后几天每天生产x吨。

340×5 + (15-5-3)x = 4500

1700 + 7x = 4500

7x = 2800

x=400

推荐阅读：
Finding Out Which Content Is Unacceptable For Your Website　 The Custom Sort String Algorithm with Count and Write　 Algorithms to Count the Number of Palindromic Substrings　 Depth First Search Algorithm to Find Leaves of a Binary Tree　 Understanding The Math Before Investing In Stocks　 Don’t Owe A Thing: Tips for Bloggers Filing Taxes　 The Quirky Quad Targets Millennials　 Social Media, FOMO and Teenage Anxiety　 Yee’s Appeal Dismissed　 What Bloggers Can Learn From Halloween