为什么linux按照课本运行不了，老是报错啊

PATH=/bin:/sbin:/usr/bin:/usr/sbin:/us r/local/bin:/usr/local/sbin:~/bin
export path
echo -e"You SHOULD input 2 number,Iwi l cross them!\n"
read -p"first number:"firstnu
read - p"second number:"secnu
total=$(($firstnu*$secnu))
echo -e' nThe result of $firstnux$s enu is=>$total"

运行结果总是报错:
root@localhost #vim sh02.sh
rootalocalhost#shsh02.sh
eYou SHOULD input 2 number,Iwill cross them!
in first number:firstnu4
second number:secnu7
sh02.sh:行6:米:语法错误:期待操作数(错误符号是"*"

PATH=/bin:/sbin:/usr/bin:/usr/sbin:/us r/local/bin:/usr/local/sbin:~/bin
export path
echo -e"You SHOULD input 2 number,Iwi l cross them!\n"
read -p"first number:"firstnu
read - p"second number:"secnu
total=$(($firstnu * $secnu))
echo -e' nThe result of $firstnux$s enu is=>$total"
~
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