Question

( frac{a}{b+c}=frac{5}{7} cdot frac{a+c}{b}=frac{5}{4} )
( 7 a=56+5 c )
( 5 b=7 a-5 c )
( 7 a-5 c=4 a+4 c )
( 7 a-4 a=4 c+5 c )
( 3 a=9 c )
( [a=3 c )
( 40 times 3 c+4 c=56 )
( 12 c+4 c=56 )
( 16 c=5 b )
( b=frac{16}{5} c )
( =frac{31 c^{c}}{c} )
( frac{a+b}{c}=3 c+frac{16}{5} c )
( frac{51}{c}=frac{31}{5} )

# find.Q+5+ b 는 특 은 두 ?

Solution