Answer:
C = 6x - 7 units
Explanation:
Let the three sides of the triangle = A, B, and C respectively.
Given the following data;
Perimeter of triangle, P = 17x-5 units
Side A = 3x+5 units
Side B = 8x-3 units
To find side C?
The perimeter of a triangle is given by the addition of all its three (3) sides.
Mathematically, the perimeter of a triangle is given by the formula;
P = A + B + C
Making "C" the subject of formula, we have;
C = P - A - B
Substituting into the equation, we have
C = 17x - 5 - (3x + 5) - (8x - 3)
C = 17x - 5 - 3x - 5 - 8x + 3
Collecting the like terms, we have;
C = 17x - 3x - 8x - 5 - 5 + 3
C = 6x - 7 units
Therefore, the third side is 6x - 7 units long.