Answer :
[tex]\frac{4}{15}=\frac{x}{75}\\\\
Cross\ multiplication\\\\
75*4=15x\\
300=15x\ |:15\\
x=\frac{300}{15}=20\\
Answer\ is\ x=20.[/tex]
4/15=x/75 (Multiply the numerator and the denominator of the fraction on the left hand side of the equation by 5)
20/75=x/75
x=20.
20/75=x/75
x=20.