Answer :
To complete the fraction, note that the numerator 39 is obtained by multiplying 13 by 3:
[tex]$$
13 \times 3 = 39.
$$[/tex]
Since the fractions must be equivalent, you multiply the denominator by the same factor. Multiplying 15 by 3 gives:
[tex]$$
15 \times 3 = 45.
$$[/tex]
Thus, the fraction equivalent to [tex]$\frac{13}{15}$[/tex] is [tex]$\frac{39}{45}$[/tex].
The number to fill in the box is [tex]$\boxed{45}$[/tex].
[tex]$$
13 \times 3 = 39.
$$[/tex]
Since the fractions must be equivalent, you multiply the denominator by the same factor. Multiplying 15 by 3 gives:
[tex]$$
15 \times 3 = 45.
$$[/tex]
Thus, the fraction equivalent to [tex]$\frac{13}{15}$[/tex] is [tex]$\frac{39}{45}$[/tex].
The number to fill in the box is [tex]$\boxed{45}$[/tex].