SOLUTION: The second angle of a triangle is twice as large as the first angle. The third angle is 12degrees more than four times the first angle. How large are the angles?

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Question 405927: The second angle of a triangle is twice as large as the first angle. The third angle is 12degrees more than four times the first angle. How large are the angles?
Answer by algebrahouse.com(1659) About Me  (Show Source):
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"The second angle of a triangle is twice as large as the first angle. The third angle is 12degrees more than four times the first angle. How large are the angles?"

x = first angle
2x = second angle {second angle is twice as large as first}
4x + 12 = third angle {twelve more than four times the first}

All angles of a triangle add up to 180.

x + 2x + 4x + 12 = 180 {added up all angles and set equal to 180}
7x + 12 = 180 {combined like terms}
7x = 168 {subtracted 12 from both sides}
x = 24 {divided both sides by 7}
2x = 48 {substituted 24, in for x, into 2x}
4x + 12 = 108 {substituted 24, in for x, into 4x + 12}

24, 48, and 108 are the angles
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