mình làm twungf phần trc nhé
2^12 x 3^5 - 2^12 x 3^4 / 2^12 x 3^6 + 2^12 x 3^5
= 2^12 x (3^5 - 3^4) / 2^12 x (3^6 + 3^5)
=3^5 - 3^4 / 3^6 + 3^5
=3^4 x (3 - 1)/ 3^4 x (3^2 +3)
=2/9+3
=2/12
=1/6
5^10 x 7^3 - 25^5 x 49^2 / 125^3 x 7^3 + 5^9 x 14^3
=5^10 x 7^3 - 5^10 x 7^4 / 5^9 x 7^3 + 5^9 x 14^3
=5^10 x (7^3 - 7^4) / 5^9 x (7^3 + 14^3)
=5 x (7^3 - 7^4) / 7^3 + 14^3
=5 x 7^3-7^4/7^3 + 14^3
=5 x 7^3 x (1 - 7) / 7^3 x ( 1 + 2^3)
=5 x 1-7/ 1+2^3
= 5-35/1 + 2^3
=-10/3
vậy sẽ bằng
1/6 +10/3
=7/2
