8+5-2/6*4c=8
c=3.75
What you have written is :
8 + 5 - (2/6)* 4c = 8 simiplify
13 - (2/6) * 4c = 8 subtract 13 from both sides
-(2/6)* 4c = -5 divide both sides by 4
-(2/6) c = -5/4 multiply both sides by -(6/2)
c = (-5/4)(-6/2) = 30/8 = 15/4 = 3,75
