Their error is that they divided 12 by 30, instead of 30 by 12 in order to get the price per pair
the correct unit price is $2.50 per pair
2.5 * 12 = 30
If you solve for x the answer is x<-8
Multiply 3.3 by everything in the parenthesis.
3.3x - 26.4 - x = 1.2
Combine like terms.
2.3x - 26.4 = 1.2
Add 26.4 to both sides.
2.3x = 27.6
Divide 2.3 on both sides.
x = 12
Hope this helps!
