Respuesta :

Underhill
(2/3)*x - (1/2)*x = 3
*make common denominators
(2*2)/(2*3)*x - (3*1)/(3*2)*x = 3
(4/6)*x - (3/6)*x = 3
(1/6)*x = 3
x = 3*(6/1)
x = 3*6
x = 18 gallons of gas