BC = 6x + 6,
AB = 8 +9, and
AC = 141.
Find BC

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.

step-by-step explanation: