5. A triangle has side lengths 3x2 + 5x –1, 6x2 + 5, -7x +1.
Which of the following expressions represents the perimeter of the triangle?
A. 9x2 + 2x + 5
B. 9x2 – 2x + 5
c. 9x2 + 2x + 4-1
D. 9x2 – 5x + 7x + 5