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The perimeter, in units, of the triangle is 12x^2 + 8x - 6.What is the length, in units, of the third side?

User CiucaS
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1 Answer

18 votes
18 votes

Step 1: Write out the formula for finding the perimeter of a triangle


p=a+y+z
\begin{gathered} \text{ Where} \\ p=\text{ the perimeter of a triangle} \\ a,y,\text{ and }z\text{ are the thre}e\text{ sides of the triangle} \end{gathered}

Step 2: Write out the given values and substitute them into the formula


p=12x^2+8x-6,a=3x^2-5x,y=7x^2+8,z=?

Therefore,


\begin{gathered} z+3x^2-5x+7x^2+8=12x^2+8x-6 \\ z+3x^2+7x^2-5x+8=12x^2+8x-6 \\ z+10x^2-5x+8=12x^2+8x-6 \\ \text{hence} \\ z=12x^2-10x^2+8x+5x-6-8 \\ z=2x^2+13x-14 \end{gathered}

Hence the

User Danny Bullis
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