Answer: QR is 8 units long
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Explanation:
R is between Q and S and on segment QS, allowing us to say
QR + RS = QS
because of the segment addition postulate.
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Use substitution and solve for QR
QR + RS = QS
QR + 11 = 19
QR = 19 - 11 .... subtracting 11 from both sides
QR = 8
