28^15x3^17/84^16
=28^15x3^17/(28x3)^16
=28^15x3^17/28^16x28^16
=3/28
Rút gọn biểu thức:
\(\frac{28^{15}.3^{17}}{84^{16}}\)\(=\frac{\left(2^2.7\right)^{15}.3^{17}}{\left(2^2.3.7\right)^{16}}\)
\(=\frac{2^{30}.7^{15}3^{17}}{2^{32}.3^{16}7^{16}}\)
\(=\frac{3}{2^2.7}=\frac{3}{28}\)
\(\frac{28^{15}\cdot3^{17}}{84^{16}}\)
=\(\frac{28^{15}\cdot3^{17}}{28^{16}\cdot3^{16}}\)
=\(\frac{1\cdot3}{28\cdot1}\)(rut gon)
=\(\frac{3}{28}\)