Answer:
x = 6
Explanation:
Since the line segment is an angle bisector then the following ratios are equal
=
( cross- multiply )
78(6x - 1) = 42(10x + 5) ← distribute parenthesis on both sides )
468x - 78 = 420x + 210 ( subtract 420x from both sides )
48x - 78 = 210 ( add 78 to both sides )
48x = 288 ( divide both sides by 48 )
x = 6