Solve (d-1)/5 = (d-3)/3

\(\frac{d-1}{5}=\frac{d-3}{3}\)

 

Cross-multiply.

\((3)(d-1)=(5)(d-3)\)

 

Distribute.

\(3d-3=5d-15\)

 

Subtract 3d from both sides.

\(-3=5d-3d-15\)

 

Add 15 to both sides.

\(-3+15=5d-3d \\~\\ 12=2d\)

 

Divide both sides by 2.

\(\frac{12}{2}=d \\~\\ 6=d\)