Bonjour ;
[tex]8^5 \times 8^{12} = 8^{5 + 12} = 8^{17} .[/tex]
[tex]2^7 \times 2^9 = 2^{7 + 9} = 2^{16} .[/tex]
[tex]0,7^{11} \times 0,7^{-10} = 0,7^{11-10} = 0,7^1 = 0,7 .[/tex]
[tex](-4)^4 \times 4 = 4^4 \times 4 = 4^{4 + 1} = 4^5 .[/tex]
[tex]\dfrac{2^8}{2^6} = 2^{8 - 6} = 2^2 = 4[/tex]
[tex]\dfrac{(-9)^7}{(-9)^4} = (- 9)^{7 - 4} = (-9)^3 = - 9^3 = - 729 .[/tex]
[tex]\dfrac{16^{10}}{16} = 16^{10 - 1} = 16^9 .[/tex]
[tex]\dfrac{(-3)^{100}}{(-3)^{23}} = (-3)^{100-23} = (-3)^{77} = - 3^{77} .[/tex]
