Answer:
x = 11.5
Step-by-step explanation:
An angle bisector is a line, ray, or segment that divides an angle into two congruent angles.
The Angle Bisector Theorem states that in a triangle, an angle bisector divides the opposite side into segments proportional to the lengths of the other two sides.
In triangle ABC, line segment AD bisects angle BAC, so:
[tex]\dfrac{DB}{AB}=\dfrac{DC}{AC}[/tex]
Substitute the given values:
[tex]\dfrac{x}{31}=\dfrac{20-x}{23}[/tex]
Cross multiply:
[tex]23x=31(20-x)[/tex]
Solve for x:
[tex]23x=620-31x\\\\\\23x+31x=620-31x+31x\\\\\\54x=620\\\\\\\dfrac{54x}{54}=\dfrac{620}{54}\\\\\\x=11.481481481...\\\\\\x=11.5\; \sf (nearest\;tenth)[/tex]
Therefore, the value of x is 11.5, rounded to the nearest tenth.