Question 748512
these are proportions so you can multiply the denominators on each side by the numeratpr of the other, to get rid of the fracyions

you get
12b -bp =12p
and
12b = 24p -pb

rearrange these so that you have the b term on one side and the other two terms on the other.  then minus one from the other, to get
24b/36 = p
i.e. p = 2/3rds b

if you substuitue this into one of the equations above, for eveyr time you have a 'p' then you will now get an equation which only has b's in it.

2b^2 -12b = 0

this can now be solved
b=0 or b =6