Answer:
[tex]\frac{2}{5}j^{2}[/tex]
Step-by-step explanation:
Let
j ------> the number
we know that
The square of a number is equal to multiply the number by itself
so
The square of j is
[tex]j*j=j^{2}[/tex]
so
Two-fifths of the square of a number j is the same that multiply the fraction 2/5 by the square of j
[tex]\frac{2}{5}j^{2}[/tex]