Based on the equation given, the value of the string will be $10.50.
It should be noted that 1 yard = 36 inches.
Therefore, 108 inches = 3 yards
Since the string is on sale for $3.50 a yard, the cost of 3 yards will be:
= $3.50 × 3
= $10.50
In conclusion,the answer is $10.50.
Learn more about equations on:
https://brainly.com/question/13763238