Can someone explain this step by step pls :)

Ok so we know that the angle of a straight line is 180 on both sides

We have to find x.

The sum of 4x+6 and 11x-6 will equal 180

Lets add them together to equal 180

15x=180

Now we divide both sides by 15 to remove the 15

We get x=12

Now lets insert 12 into 4x+6 to get the answer we need

4(12)+6= ABD Angle

48+6=ABD Angle

54=ABD Angle

The answer is 54°