Answer:
∠A = 32°
Explanation:
Supplementary angles total 180°.
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∠A +∠B = 180° . . . . . sum of the two supplementary angles
(2x -16)° +(5x +28)° = 180° . . . . . . substitute the given expressions
7x +12 = 180 . . . . . . . . . . . . . . divide by °, collect terms
7x = 168 . . . . . . . . . . . . . . . subtract 12
x = 24 . . . . . . . . . . . . . . divide by 7
We can use this value of x to find the angle measures:
∠A = (2x -16)° = (2×24 -16)° = 32°
∠B = (5x +28)° = (5×24 +28)° = 148°
The measure of angle A is 32°.
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Check
32° +128° = 180°