makefile:2: *** make後のエラー、解決方法

質問事項
今日、helloworld.cとMakefileのファイルを作成しました。
hellworld.cの中身は以下の通りです。

#include
The contents of the Makefile are as follows:
hello:helloword.c
      gcc -o hello helloword.c
Then make gives the following error:
makefile:2: *** missing separator. stop.
The overall effect is shown in the code below:
root@ubuntu:~/lesson/chap1/1-1# ls
helloword.c makefile
root@ubuntu:~/lesson/chap1/1-1# make
makefile:2: *** missing separator. stop.
Solution


 In the
gcc -o hello helloword.c
preceded by the TAB key, not the space space space space ....