Final answer:
To calculate the perimeter of the triangular fence, sum the lengths of the sides (3x+4, y-5, and 7x-1) to get 10x+y-2. The correct multiple-choice answer is 'a. 10x+y-2'.
Step-by-step explanation:
The student is asked to calculate the total perimeter of a triangular fence with sides of length 3x+4, y-5, and 7x-1. To find the perimeter of a triangle, we simply add up the lengths of all the sides. Therefore, the perimeter (P) can be calculated as follows:
P = (3x+4) + (y-5) + (7x-1)
Simplifying the expression, we combine like terms:
P = 3x + 4 + y - 5 + 7x - 1
P = 10x + y - 2
So the total perimeter of the triangular fence is 10x + y - 2.
In conclusion, if we give an mcq answer in the final answer, the correct option would be a. 10x+y-2.