Answer:
4) c = 38
5) x = 50
Explanation:
4) The marked angles are a "linear pair", meaning their total is 180°:
3c° +(2c -10)° = 180°
5c = 190 . . . . . . . divide by °, add 10, collect terms
c = 38 . . . . . . . . . divide by 5
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5) The interior angle at C brings the total of the marked angle and the interior angle to 360°
330° + (interior angle) = 360°
(interior angle) = 30° . . . . . . . . . subtract 330°
The interior angles of the triangle total 180°, so we have ...
x° +2x° +30° = 180°
3x = 150 . . . . . . . . . . . . . divide by °, subtract 30
x = 50 . . . . . . . . . divide by 3