Answer
$c=5 $
Work Step by Step
We need to get the c alone. Thus, we cancel out the subtraction by adding 2 on both sides. This leaves us with the equation 2 1/2=1/2c. In this equation, c is being multiplied by a fraction, which we must cancel out. In order to cancel out a fraction being multiplied by a variable, we multiply both sides of the equation by the reciprocal of the fraction, which is the fraction flipped upside down. (For instance, the reciprocal of ⅖ is 5/2).
Thus, we multiply both sides of the equation by 2/1 to obtain that c=5.
We plug 5 in for c and confirm that our answer is, indeed, correct.