Answer:
x = 2
Explanation:
Given that the measure of segment BC must equal the addition of the measure of segment BA plus the measure of segment AC, we can write this in equation form:
BC = BA + AC
then we replace them with the measure information they provide:
12 x + 4 = 7 x - 4 + 8 x + 2
and we solve for x in the equation:
12 x + 4 = 15 x - 2
subtract 12 x from both sides:
4 = 15 x - 12 x - 2
4 = 3 x - 2
add 2 on both sides
4 + 2 = 3 x
6 = 3 x
x = 6/3
x = 2