Răspuns:
[tex] {25}^{10} = ( {5}^{2} )^{10} = {5}^{20} [/tex]
[tex] {125}^{7} = ( {5}^{3} )^{7} = {5}^{21} [/tex]
[tex] {5}^{5} \times {5}^{20} \div {5}^{21} = {5}^{5 + 20 - 21} = {5}^{4} = 625[/tex]