Answer: 3 in, 20 in, x-7 in, 19 in.
Step-by-step explanation: First we must find the formula for the length of the red string. In this case, it is x - 7.
(x is the length of the blue string, in inches.)
First we go 10 - 7 = 3
Then we go 27 - 7 = 20
Then we go x - 7 = x - 7
Finally, 12 + 7 = 19 because we are already given the length of the red ribbon.