The answer is A. 12 and 8
x - y = 4
x * y = 96
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x = y + 4
x * y = 96
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(y + 4) * y = 96
y² + 4y = 96
y² + 4y - 96 = 0
y² + 12y - 8y - 96 = 0
(y² + 12y) - (8y + 96) = 0
y(y + 12) - 8(y + 12) = 0
(y + 12)(y - 8) = 0
y + 12 = 0 or y - 8 = 0
y = -12 or y = 8
Since, the numbers are positive, then the only solution for y is 8.
x - y = 4
y = 8
x - 8 = 4
x = 8 + 4
x = 12