Question

數(shù)學(xué)與生活！                                                                                                             

Answer 1

解：設(shè)買1 聽(tīng)果奶需x元，則買一聽(tīng)可樂(lè)需(x＋0.5) 元。由題得方程       
  x＋4(x＋0.5) ＝20-3        
  x＋4 x＋2=17           
  5 x=15              
     x＝3      
當(dāng)x＝3  時(shí)，x＋0.5 ＝3.5 
 答：買1 聽(tīng)果奶需3 元，買一聽(tīng)可樂(lè)需3.5 元。