Question 171936
Let x=the unknown number 
when we subtract it from 5, we get:
(5-x); twice (5-x) is:
2(5-x) and we are told that this equals 8, so:
2(5-x)=8 get rid of parens (distributive law)
10-2x=8  subtract 10 from each side
10-10-2x=8-10
-2x=-2  divide each side by -2
x=1-----------------------the unknown number
CK
5-1=4
2*4=8
Hope this helps---ptaylor