The length is 17 and x=5
13 times 3x+2 = 221 so solve by dividing 221 by 13= 17.
Now we know that 3x+2= 17 so 3x= 15
x=5
ANSWER

EXPLANATION
The given product is:

We expand using the distributive property to obtain:

Extract the perfect squares to get:

Expand further to get;

This simplifies to,

Answer:
700 meters
Step-by-step explanation:
multiply the length value by 10