The triangles are congruent so [tex]2d+10[/tex] and [tex]45-3d[/tex] are the same
So we have
[tex]2d+10=45-3d[/tex]
⇒[tex]5d+10=45[/tex]
⇒[tex]5d=35[/tex]
⇒[tex]d=7[/tex]
Plug in:
[tex]2d+10=2(7)+10=14+10=24[/tex]
[tex]45-3d=45-3(7)=45-21=24[/tex]
[tex]d+8=7+8=15[/tex]
