Answer:
BC = 7
Step-by-step explanation:
AB + BC = AC
Substitute values for the line segments:
6 + BC = 13
Isolate line segment BC by subtracting both sides by 6:
6 - 6 + BC = 13 - 6
0 + BC = 13 - 6
BC = 7
Check your work:
6 + 7 = 13
13 = 13
Correct!