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3. Find the value of x for which ABCD must be a parallelogram(X+3)*(2x - 1)

3. Find the value of x for which ABCD must be a parallelogram(X+3)*(2x - 1)-example-1
User RCIX
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1 Answer

7 votes

For the shape ABCD to be a parallelogram, the sides AB and CD must be parallel:


AB||CD

Hence, line BD is the transversal.

Note that angles ABD and CDB are alternate interior angles. By definition, the angles will be equal:


m\angle ABD=m\angle CDB

Therefore, substituting the values of the angles will yield the following equation:


x+3=2x-1

Solving the equation for x:


\begin{gathered} 2x-x=3+1 \\ x=4 \end{gathered}

Therefore, the correct option is the THIRD OPTION.

User Arrumaco
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