Hello!
Supplementary angles add up to 180 degrees.
Let the unknown angle be w.
w+w+42=180
That's the right equation, because we have an angle w and an angle that's 42 degrees more than w (w+42)
Solve:
2w+42=180
Subtract 42 from both sides:
2w=180-42
2w=138
Divide both sides by 2:
w=69
Add 42:
w=69+42=111
Let's check:
69+111=180
Answers: 69 and 111 (degrees)
Hope everything is clear.
Let me know if you have any questions!
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