Answer:



Explanation:
Complementary Angles sum up to 90°, so set the two expressions equal to 90°:
90° = [3x + 20]° + [5x - 10]°
90° = [10 + 8x]°
-10° - 10°
___________
80° = [8x]°
__ __
8° 8°
[Plug this back into both expressions to get m∠B at 50° and the m∠A at 40°.]
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![20° + [3[10]]° = m∠B → 20° + 30° = 50° \\ \\ 50° = m∠B](https://img.qammunity.org/2020/formulas/mathematics/high-school/7oq442a8bapp0vhfqprofoaktajooyfsz6.png)
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