Answer:
x = 12
Step-by-step explanation:
Since the triangles are similar then the ratios of corresponding sides are equal, that is
[tex]\frac{AB}{DE}[/tex] = [tex]\frac{BC}{EF}[/tex] , substitute values
[tex]\frac{x}{6}[/tex] = [tex]\frac{8}{4}[/tex] ( cross- multiply )
4x = 48 ( divide both sides by 4 )
x = 12