\(a,5^3\times5^7=5^{3+7}=5^{10}\)

\(102^{11}\times102^5=102^{11+5}=102^{16}\)

\(19^3\times19^7\times19^5=19^{3+7+5}=19^{15}\)

\(b,x^m\times x^n\times x^p\times x^q=x^{m+n}\times x^p\times x^q=x^{m+n+p}\times x^q=x^{m+n+p+q}\)