求英语数学应用题解答,急
问题描述：
求英语数学应用题解答,急
鸡肉每磅6美元,香肠每磅3美元,米饭每磅1美元.她在13又二分之一磅的食物上花了42美元.她买的米饭是香肠的2倍.
Write a system of three equations that represents how much food Simone purchased
答
鸡肉x,香肠y,米饭z
x+y+z=13.5
6x+3y+z=42
z=2y
解得
x=4.5
y=3
z=6