x - price of one pair socks
The equation:
[tex]5(2x)+5\times12=125[/tex]
[tex]10x+60=125[/tex] subtract 60 from both sides
[tex]10x=65[/tex] divide both sides by 10
[tex]\boxed{x=6.5}[/tex]
5(2x) - five sisters · two pairs of socks
5 · 12 - five scraves
125 - total cost