Answer:
10 units
Step-by-step explanation:
We are given that
BD=x+29
AD=x+39
AC=20
BC=x+19
AC=AB+BC
20=AB+x+19
AB=20-x-19=1-x
AD=AB+BD
[tex]x+39=1-x+x+29[/tex]
[tex]x=30-39=-9[/tex]
Substitute the value of x=-9
Then , we get BC=[tex]-9+19=10[/tex] units
Answer: BC=10 units
