Componendo-Dividendo: if $a:b = c:d$, then—

Question

Accepted Answer

$\dfrac{a+b}{a-b} = \dfrac{c+d}{c-d}$

Answer

$\dfrac{a+b}{a-b} = \dfrac{c-d}{c+d}$

Answer

$a+b = c-d$

Answer

$\dfrac{a}{b-a} = \dfrac{c}{d-c}$

Componendo-Dividendo: if a:b=c:da:b = c:da:b=c:d, then—