We want to calculate the value of
[tex]3x-1[/tex]
However, x is unknown. For BD is "angle bisector"
[tex]3x-1=34-2x[/tex]
Let us solve that equation for x:
[tex]3x+2x=34+1[/tex]
(-2x was sent to the left-hand side, and -1 was sent to the right-hand side)
[tex]5x=35[/tex][tex]x=7[/tex]
Then,
[tex]3x-1=3(7)-1=21-1=20[/tex]
Thus,
[tex]m\measuredangle ABD=20[/tex]
