Respuesta :

[tex]x = \frac{1}{2} (x + 60 - 20)[/tex]

[tex]x = \frac{1}{2} (x + 40)[/tex]

[tex]x = \frac{1}{2}x + 20[/tex]

[tex]x - \frac{1}{2}x = 20[/tex]

[tex] \frac{1}{2}x = 20[/tex]

[tex]x = 20 \times 2[/tex]

[tex]x = 40[/tex]
fishtank

The answer is b) 40

Have a great day!

-Fishtank