<span>The answer would be 20.
The question is asking you to find the value of the expression for when c = 100, so we have to put 100 where c is in the equation. Given that fact, we start with c/5, then put the 100 in for c.
c/5 = ??
100/5 = 20. </span>
This is the answer

if substitute 1 and 2 and 3 as x then the points will be :

and that's the picture
good luck