8 = 4 + 2c
move 4 to the other side
the sign always changes when moving to the other side
8-4= 4-4+2c
8-4= 2c
4= 2c
divide both sides by 2 to get c by itself
4/2= 2c/2
Cross out 2 and 2 divide by 2 and then becomes 1*1*c= c
c= 4/2
Answer: c= 2