Answer:
Option B: 3x + 3y - 3
Step-by-step explanation:
In an isosceles triangle, the two congruent sides are equal.
We are told the base is; x - y - 2 units
Now let each of the congruent sides be represented as A.
Thus the perimeter equation will be;
P = 2A + x - y - 2
Now, we are told that the perimeter is; 7x + 5y - 8 units
Thus;
7x + 5y - 8 = 2A + x - y - 2
Rearranging gives;
7x - x + 5y + y - 8 + 2 = 2A
2A = 6x + 6y - 6
Divide through by 2 to give;
A = 3x + 3y - 3 units
