Answer: 60
Step-by-step explanation:
Since AB and BC creates AC, we can add them together to find x, then use that to find the value of BC.
8x+9+6x+6=141 [combine like terms]
14x+15=141 [subtract both sides by 15]
14x=126 [divide both sides by 14]
x=9
Now that we have found the value of x, we can plug that into BC.
6(9)+6 [multiply]
54+6 [add]
60
Now, we know the length of BC is 60.
