Answer:
x = 6
Step-by-step explanation:
Given that the line segment is an angle bisector then the following ratios are equal
[tex]\frac{42}{78}[/tex] = [tex]\frac{6x-1}{10x+5}[/tex], that is
[tex]\frac{7}{13}[/tex] = [tex]\frac{6x-1}{10x+5}[/tex] ( cross- multiply )
13(6x - 1) = 7(10x +5) ← distribute parenthesis on both sides
78x - 13 = 70x + 35 ( subtract 70x from both sides )
8x - 13 = 35 ( add 13 to both sides )
8x = 48 ( divide both sides by 8 )
x = 6