If the two identical solid cubes of side x are joined end to end, then the total surface area of the resulting cuboid is 12x2. Is it true?
tsa = 2{ lb + bh + lh}
= 2 { 2x*x + x*x + 2x*x}
= 2 { 2x^2 + x^2 + 2x^2}
= 2 { 5x^2}
= 10x^2
but, 10x^2 is not equal to 12x^2 ,
therefore, it is false
= 2 { 2x*x + x*x + 2x*x}
= 2 { 2x^2 + x^2 + 2x^2}
= 2 { 5x^2}
= 10x^2
but, 10x^2 is not equal to 12x^2 ,
therefore, it is false