a)
[tex] \frac{3x - 2y - 7}{7} = \frac{2y - x - 3}{3} [/tex]
[tex]9x - 6y - 21 = 14y - 7x - 21[/tex]
[tex]9x - 6y = 14y - 7x[/tex]
[tex]16x - 6y = 14y[/tex]
[tex]16x = 20y[/tex]
[tex] \frac{x}{y} = \frac{20}{16} [/tex]
b)
[tex] \frac{a}{2.4} = \frac{b}{4} [/tex]
[tex]4a = 2.4b[/tex]
[tex]4a = \frac{24b}{10} [/tex]
[tex]40a = 24b[/tex]
[tex]10a = 6b[/tex]
[tex]5a = 3b[/tex]
=> a=3 b=5
ba=53