Answer:
6x - 1
Step-by-step explanation:
Okay this is basically polynomial algebra:
1. Add the value of the lengths already given.
like terms: 3x + x = 4x, -4 + 2 = -2. Now you're left with, 4x - 2.
2. Find the difference between the perimeter and the sum of the lengths.
(10x -3) + (4x + 2) = 6x - 1
