Answer:
10.8 yards
Explanation:
Since she has 19.7 yards left over, the amount she used for curtains is ...
84.5 - 19.7 = 64.8 . . . . yards
Then each of the 6 identical curtains used 1/6 of this amount, or ...
(64.8 yards)/6 = 10.8 yards
_____
You can write an equation if you like. Let c represent the yardage used for each curtain. Then the total number of yards of fabric Jennifer has is ...
6c +19.7 = 84.5
We can find the value of c by subtracting 19.7, then dividing by 6 (as above).
6c = 64.8 . . . . subtract 19.7
c = 10.8 . . . . . divide by 6
Jennifer used 10.8 yards of fabric per curtain.