Two angles measure (5y + 62°) and (22° + y). If the two angles are supplementary (their sum is 180°), find the value of y in degrees.
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A32°
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B16°
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C8°
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D24°
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E1°
Answer
Correct Answer: 16°
Explanation
Introduction / Context: This question checks a basic geometry fact: supplementary angles add up to 180°. Once you translate the statement into an equation, it becomes a simple linear equation in y.
Given Data / Assumptions:
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• Angle 1 = (5y + 62°)
• Angle 2 = (22° + y)
• Supplementary means: Angle 1 + Angle 2 = 180°
• Required: y (in degrees)
Concept / Approach: Use the definition of supplementary angles: (5y + 62) + (22 + y) = 180. Combine like terms (y terms together and constants together), then isolate y by basic algebra.
Step-by-Step Solution: 1) Form the equation from supplementary condition: (5y + 62) + (22 + y) = 180 2) Combine y terms: 5y + y = 6y 3) Combine constants: 62 + 22 = 84 4) So the equation becomes: 6y + 84 = 180 5) Subtract 84 from both sides: 6y = 96 6) Divide both sides by 6: y = 16 7) Therefore y = 16°.
Verification / Alternative check: Substitute y = 16: Angle 1 = 5*16 + 62 = 80 + 62 = 142°. Angle 2 = 22 + 16 = 38°. Sum = 142° + 38° = 180°, so the condition holds exactly.
Why Other Options Are Wrong: • 32°, 24°, 8°, 1°: substituting any of these values does not make the two expressions add to 180°.
Common Pitfalls: • Treating supplementary as “equal” instead of “sum to 180°”. • Forgetting to combine y terms correctly (5y + y = 6y).
Final Answer: 16°