Answer:
x = 9
Step-by-step explanation:
[tex] \triangle ABC\sim \triangle ADE.... (given) [/tex]
[tex] \therefore \frac{AB}{AD} = \frac{BC}{DE}.... (csst) [/tex]
[tex] \therefore \frac{28}{20} = \frac{2x+3}{15}[/tex]
[tex] \therefore \frac{7}{5} = \frac{2x+3}{15}[/tex]
[tex] 5(2x+3) = 7\times 15[/tex]
[tex] 10x+15 = 105[/tex]
[tex] 10x = 105-15[/tex]
[tex] 10x = 90[/tex]
[tex] x = \frac {90}{10}[/tex]
[tex] x = 9[/tex]
