To determine which solution is correct, we need to substitute each pair \((x, y)\) into the equation \(1.5x - 2y = 8\) and check if the equation holds true.
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Fiona's solution: (4, 7)
\[ 1.5(4) - 2(7) = 6 - 14 = -8 \quad \text{(not a solution)} \]
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Sam's solution: (-4, -7)
\[ 1.5(-4) - 2(-7) = -6 + 14 = 8 \quad \text{(this is a solution)} \]
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Mary's solution: (4, -7)
\[ 1.5(4) - 2(-7) = 6 + 14 = 20 \quad \text{(not a solution)} \]
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Peter's solution: (-4, 7)
\[ 1.5(-4) - 2(7) = -6 - 14 = -20 \quad \text{(not a solution)} \]
The only solution that satisfies the equation \(1.5x - 2y = 8\) is Sam's solution \((-4, -7)\).