So, we have to sum the three numbers, square the result, and then multiply the result by three.
We have
[tex] a+b+c = 2+3+4 = 9 [/tex]
If we square this result, we get
[tex] 9^2=81 [/tex]
If we multiply this by 3, we have
[tex] 81 \cdot 3 = 243 [/tex]
