The answer is: 10 x¹³ y¹⁰ .
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1x^8 2y^(10) 5x^5 =
1 2 5 x^8 x^5 y^(10) =
10 x^(8+5) y^(10) =
10 x^(13) * y^(10) = 10 x^(13) y^10 ; write as:
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10 x¹³ y¹⁰ .
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