Answer :
[tex]\\ \sf\longmapsto \dfrac{x}{5}=\dfrac{16}{21}[/tex]
[tex]\\ \sf\longmapsto 21x=16(5)[/tex]
[tex]\\ \sf\longmapsto 21x=80[/tex]
[tex]\\ \sf\longmapsto x=\dfrac{80}{21}[/tex]
[tex]\\ \sf\longmapsto x=3.6[/tex]
Step-by-step explanation:
[tex] \frac{x}{5} = \frac{16}{21} \\ by \: cross \: multiplication \\ x \times 21 = 5 \times 16 \\ 21x = 80 \\ x = \frac{80}{21} \\ x = 3.8[/tex]