The answer is 4 pairs.
Think of having x number of pairs, and $4.29x for the price of those pairs. 8.58 is standalone, so we focus on writing the equation:
[tex]8.58+4.29x=25.74\\4.29x=25.74-8.58\\4.29x=17.16\\\frac{4.29}{4.29}=\frac{17.16}{4.29} (division)\\x=4[/tex]
