Hey there!
A quadrilateral has 360 degrees. So add all the degrees together to 360. 9x+1+5x-12+8x+61+90=360. 90 degrees is in the bottom left corner. Combine like terms. 22x+140=360. Subtract 140 from each side. 22x=220. Divide 22 on each side to get x=10. Plug in 10 for x in angle D. 5(10)-12=38. The measure of angle D is 38 degrees.
I hope this helps!
Some parts are missing in the queston. Find attached the picture with the complete question
Answer:

Explanation:
Let's put the information in a table step-by step.
(number of remaining students)
Juniors Seniors
Condition
- Twice juniors as seniors 2(S - 15)
- 3/4 of the juniors left 1/4×2(S - 15)
- 1/3 of seniors left 2/3×(S - 15)
At the end, there were 8 more seniors than juniors:
- 2/3×(S - 15) - 1/4×2(S - 15) = 8
Now you have obtained one equation, which you can solve to find S, the number of senior students, and then the number of junior students.
Solve the equation:



- Addtion property of equalities:


- Division property of equalities:

That is the number of senior students that came out to the information meeting, but the number of students remaining to perform in the school musical is (from the table above):

Just substitute S with 153 fo find the number of students that remained to perfom in the musical:


Step-by-step explanation:
........understood..............
5b-2=13 add 2 to both sides
5b=15 divide both sides by 5
b=3
The length of CD is 7-3=4.
Therefore, if we dilate by a scale factor of 3, the length is 4(3) = 12