Answer:
[tex]\sf x = 6\dfrac{2}{3} \ \ or \ \ 6.67 \ (rounded \ to \ nearest \ hundreth)[/tex]
Build a proportional equation:
[tex]\rightarrow \sf \dfrac{AB}{AD} = \dfrac{BC}{DE}[/tex]
[tex]\rightarrow \sf \dfrac{10}{x+10} = \dfrac{6}{10}[/tex]
[tex]\rightarrow \sf 10(10) = 6(x+10)[/tex]
[tex]\rightarrow \sf 100 = 6x+60[/tex]
[tex]\rightarrow \sf 40= 6x[/tex]
[tex]\rightarrow \sf x = 40/6[/tex]
[tex]\rightarrow \sf x = \dfrac{20}{3}[/tex]
[tex]\rightarrow \sf x = 6\dfrac{2}{3}[/tex]
