Answer:
[tex]\boxed{x=15}[/tex]
Step-by-step explanation:
[tex]\frac{3}{4} =\frac{x}{20}[/tex]
[tex]\sf Cross \ multiply.[/tex]
[tex]4 \cdot x = 20 \cdot 3[/tex]
[tex]4x=60[/tex]
[tex]\sf Divide \ both \ sides \ by \ 4.[/tex]
[tex]\frac{4x}{4} =\frac{60}{4}[/tex]
[tex]x=15[/tex]
