First: (8xy)a
Second: (8xy)b
Where a and b are relatively prime expressions [GCF(a, b) = 1].
Examples
a = 2x
b = 3y
then your answer is
(8xy)(2x) = 16x²y
(8xy)(3y) = 24xy²
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a = 5x²
b = 7y³
(8xy)(5x²) = 40x³y
(8xy)(7y³) = 56xy⁴