Answer:
C. [tex]19[/tex]
Step-by-step explanation:
BD = DC because angles ADC and ADB are right angles.
Thus, [tex]4x-5=2x+7[/tex]
Add 5 to both sides:
[tex]4x-5+5=2x+7+5[/tex]
[tex]4x=2x+12[/tex]
Subtract 2x from both sides:
[tex]4x-2x=2x+12-2x[/tex]
[tex]2x=12[/tex]
Divide both sides by 2:
[tex]\frac{2x}{2}=\frac{12}{2}[/tex]
[tex]x=6[/tex]
DC [tex]=4x-5[/tex]
[tex]=4(6)-5[/tex]
[tex]=24-5[/tex]
[tex]=19[/tex]
