Answer:
BC = 21
Step-by-step explanation:
AB + BC = AC
[tex]7x + 8 + 3x + 6 = 64[/tex]
[tex]10x + 14 = 64[/tex]
[tex]10x = 50[/tex]
[tex]x = 5[/tex]
BC = 3(5) + 6 = 21
