$a$) `{2x+3}/{24} = {3x-1}/{32}`
`⇔ 32(2x+3) = 24(3x-1)`
`⇔ 64x +96 = 72x - 24`
`⇔ 96+24 = 72x - 64x`
`⇔ 120 = 8x`
`⇔ x = 15`
Vậy `x=15`.
$b$) `{13x-2}/{2x+5} = {76}/{17}` `(x \ne -5/2)`
`⇔17(13x-2) = 76(2x+5)`
`⇔ 221x - 34 = 152x + 380`
`⇔ 221x - 152x = 380 + 34`
`⇔ 69x = 414`
`⇔ x =6` ($TMĐK$)
Vậy `x=6`.