Find the measures of the supplementary angles

19x + 40 and x are supplementary angles. Determine the measure of each angle.

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Supplementary angles add up to 180°.

x + 19x + 40 = 180 {added the two angles and set equal to 180°}
20x + 40 = 180 {combined like terms}
20x = 140 {subtracted 40 from each side}
x = 7 {divided each side by 20}
19x + 40 = 173 {substituted 7, in for x, into 19x + 40}

The two angles are 7° and 173°
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