Question 1199972
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<pre>

      AC    =  BD

    8x-4    = 5x+5

    8x - 5x = 5 + 4

      3x    =   9

       x    =   9/3 = 3

    AC = 8x-4 = 8*3-4 = 24 - 4 = 20.    <U>ANSWER</U>
</pre>

Solved.