Hey there!!
Given that line AB and CD are equal.
The total length of AB = AC + CB
... 2x+5x+7
... 7x+7
The total length of CD = CB + BD
... 5x+7+3x-4
... 8x+3
Now, these values are equal:
... 7x+7=8x+3
... -x=-4
... x=4
Find the value of BD
... 3x-4
...3(4)-4
...12-4
... 8 Is the answer.
Hope it helps!
