Question 1148414
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<pre>

     AB≅BC and CD≅BC   implies   AB≅CD.


It means


    2x+1 = 4x-11.


It implies


    1 + 11 = 4x - 2x

    12     = 2x

     x     = 12/2 = 6.


<U>PROVED</U>
</pre>

Solved, explained, and completed.