The sides of the cuboid are as follows: x, x+1 and x+2. Total surface area of a cuboid is the area of each surface added together. Therefore 2x(x+2)+2x(x+1)+2(x+2)(x+1)= 52 units².
2x²+4x+2x²+2x+2x²+6x+4= 52
6x²+12x+4=52
6x²+12x-48=0
x²+2x-8=0
Use Quadratic formula
x=2