Respuesta :

Answer:

He's 65 years old

Step-by-step explanation:

300-4x=40

-300+40=-4x

-260=-4x

65=x

Answer:

85

Step-by-step explanation:

4x - 300 = 40

    + 300 +300

------------------------

        00      340

340 ÷ 4 = 85