[tex] \dfrac{x}{5} + \dfrac{x + 4}{3} = 4 [/tex]
[tex] \dfrac{x}{5} \times \dfrac{3}{3} + \dfrac{x + 4}{3} \times \dfrac{5}{5} = 4 [/tex]
[tex] \dfrac{3x}{15} + \dfrac{5x + 20}{15} = 4 [/tex]
[tex] \dfrac{8x + 20}{15} = 4 [/tex]
[tex] 8x + 20 = 60 [/tex]
[tex] 8x = 40 [/tex]
[tex] x = 5 [/tex]
