Given:
[tex]\sf \dfrac{a\ -\ 3b}{a\ +\ 2b}\ =\ \dfrac{4}{3}[/tex]
To find: The value of a:b.
Answer:
[tex]\sf \dfrac{a\ -\ 3b}{a\ +\ 2b}\ =\ \dfrac{4}{3}[/tex]
Cross-multilpying,
[tex]\sf 3\ \times\ (a\ -\ 3b)\ =\ 4\ \times\ (a\ +\ 2b)\\\\3a\ -\ 9b\ =\ 4a\ +\ 8b[/tex]
Bringing the like terms together,
[tex]\sf 3a\ -\ 4a\ =\ 8b\ +\ 9b\\\\\\-a\ =\ 17b\\\\\\\dfrac{-a}{b}\ =\ 17\\\\\\\dfrac{a}{b}\ =\ -17[/tex]
Therefore, a:b = -17.