simplify

I'll assume you mean \((8x^6y^5)(5x^5y^{12})\). this can be expressed as \(8 \cdot 5 \cdot x^6 \cdot x^5 \cdot y^4 \cdot y^{12}\). 

 

\(8\) times \(5\) is \(40\)

using a law of exponents which states that \(a^n \cdot a^m = a^{n + m}\), we can write \(x^6 \cdot x^5 = x^{11}\) and \(y^4 \cdot y^{12} = y^{16}\).

 

so, we have \(40 \cdot x^{11} \cdot y^{16} = 40x^{11}y^{16}\) 

 

and there you have it