Final answer:
To find the length of the third side of the triangle, use the formula for the perimeter of a triangle and solve for the third side.
Step-by-step explanation:
To find the length of the third side of the triangle, we need to use the formula for the perimeter of a triangle.
The formula is P = a + b + c, where P is the perimeter and a, b, and c are the lengths of the sides.
In this case, the perimeter is given as 16x - 6, and the lengths of the first two sides are 3x + 2 and 4x - 9.
So, the equation becomes 16x - 6 = (3x + 2) + (4x - 9) + c.
Simplifying the equation, we get 16x - 6 = 7x - 7 + c.
Now, we can solve for c by subtracting 7x and 7 from both sides of the equation.
This gives us 9x - 13 = c.
Therefore, the length of the third side is 9x - 13.