The measure of the missing side is 3x^3 +2x - 7y + 9
Perimeter of a triangle
The perimeter of a triangle is equal to the sum of all the sides of the triangle. Mathematically;
P = s1 + s2 + s3
where;
s1 = s2 = -8x^3 + 2
P = -13x^3 + 2x - 7y + 3
Substitute the given parameters
-13x^3 + 2x - 7y + 3 = s3. + 2(-8x^3 + 2)
-13x^3 + 2x - 7y + 3 = s3 - 16x^3 -4
s3 = -13x^3 + 2x - 7y + 3 + 16x^3 + 6
s3 = 3x^3 +2x - 7y + 9
Hence the measure of the missing side is 3x^3 +2x - 7y + 9
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