Answer:
21
Step-by-step explanation:
(21 plus 4)=25
25 minus 7=18
~~~How I got 21~~~
I find the number that will be reasonable like 20 and work my way up
~~~Hope this helps~~~
[tex](n+4)-7=18 \\ n = 18 + 7 - 4 \\ n = 21.[/tex]