Respuesta :

so when you have ratios, some are unknowns you have to create complex fractions from them. Bring to the same donominator, and solve for x.

Ex: we have this portion:
2 -x
5-45

and we change it into fractions 

2/5 =x/25

2x9/5x9 = x/45

answer would be 18=x

in case of more  complex fractions it may become in handy. 

Your welcome!!