Step-by-step explanation:
[tex] \frac{4}{5} of \: x = 45 \\ \frac{4}{5} \times x = 45 \\ cross \: multiply[/tex]
[tex] \frac{4x}{5} = 45 \\ 4x = 45 \times 5 \\ 4x = 225 \\ divide \: both \: sides \: by \: 4[/tex]
[tex] \frac{4x}{4} = \frac{225}{4} \\ x = 56.25[/tex]
