Respuesta :

3 x - 4 y = 65

Refine :

3 x - 4 * 4 =  65

3 x - 16 = 65

Add 16 to both sides :

3 x - 16 + 16 = 65 + 16

3 x = 81

Divide both sides by 3 :

3 x / 3  = 81 / 3

x = 81 / 3

x = 27

hope this helps!