Answer:
x = 12
Step-by-step explanation:
[tex] \triangle SDE \sim \triangle SWT... (given) [/tex]
[tex] \therefore \frac{DE}{WT} =\frac{SE}{ST}... (csst) [/tex]
[tex] \therefore \frac{56}{5x+3} =\frac{40}{4x-3}[/tex]
[tex] \therefore \frac{7}{5x+3} =\frac{5}{4x-3}[/tex]
[tex] \therefore 7(4x-3) =5(5x+3)[/tex]
[tex] \therefore 28x-21=25x+15[/tex]
[tex] \therefore 28x-25x=21+15[/tex]
[tex] \therefore 3x=36[/tex]
[tex] \therefore x=\frac{36}{3}[/tex]
[tex] \therefore x=12[/tex]
