Answer: 19
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Step-by-step explanation:
T is the midpoint of PQ, which means T splits PQ into two equal parts. Those parts being PT and TQ.
Set them equal to each other and solve for x.
PT = TQ
3x+7 = 7x-9
3x-7x = -9-7
-4x = -16
x = -16/(-4)
x = 4
So,
PT = 3x+7 = 3*4+7 = 19
TQ = 7x-9 = 7*4-9 = 19
Both PT and TQ are 19 units long to help confirm the answer.