Question

(7a_5b): (7a+3b) =3:8,finda:b

Answer 1

$\frac{(7a - 5b)}{(7a + 3b)} = \frac{3}{8} \\ \\ 8 \times (7a - 5b) = 3 \times (7a + 3b) \\ 56a - 40b = 21a + 9b \\ 56a - 21a = 9b + 40b \\ 35a = 49b \\ \frac{a}{b} = \frac{49}{35}$

a:b =49:35