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Answer:
A) 42°
Explanation:
The whole is the sum of the parts. Lines AH and BC cross at right angles, so angle CDE is a right angle. Then angles CDJ and JDE will have a total of 90°.
∠CDJ +∠EDJ = 90°
3x° +(2x +10)° = 90°
5x = 80 . . . . . . . . . divide by °, collect terms, subtract 10
x = 16 . . . . . . . . divide by 5
(2x+10)° = (2(16) +10)° = 42°
Angle EDJ is 42°.