Respuesta :

4(5x-20)= -20

20x-80= -20
      +80  +80
____________

20x=60
_______
      20

x=3
Setor9
4(5x-20)=-20
20x-80=-20 ======> Add 80 to both sides
20x-80+80=-20+80
20x=60======> Divide both sides by 20
20/20x=60/20
x=3