Bonsoir ;
A = (10^5 x 2^6)/(2^2 x 10^3) = 10^5 x 2^6 x 2^(-2) x 10^(-3)
= 10^(5 - 3) x 2^(6 - 2) = 10^2 x 2^4 = 100 x 16 = 1600 .
B = (10^4 x 7^(-1))/(2^7 x 7^(-3) x 5^7) = (10^4 x 7^(-1))/((2 x 5)^7 x 7^(-3))
= (10^4 x 7^(-1))/((10^7 x 7^(-3)) = 10^4 x 7^(-1) x 10^(-7) x 7^3
= 10^(4 - 7) x 7^(-1 + 3) = 10^(-3) x 7^2
= 0,001 x 49 = 0,049 .