Answer
x=3.2
Work Step by Step
You have to set their totals to $34.60$.Tyson's yarn is $6.25$ and he needs 2 knitting needles. Jillian's yard will be $3(6.25)=18.75$ and she needs one knitting needle. Thus:
$34.60=18.75 +x+6.25+2x$ (simplify like terms)
$34.60=25+3x$ (subtract 25 from both sides)
$9.60=3x$ (divide both sides by 3 to isolate the variable)
$3.20=x$
The cost of each knitting needle is $3.20$.