Question

[tran khac hap]

Rút gọn biểu thức
a)28^15 . 3^17 
_____________
        84^16
b) 3^10 + 6^2
________________
5.3^8 + 20

Answer 1

[Đỗ Kim Lâm]

\(a.\frac{3}{28}\)

\(b.\frac{9}{5}\)

Answer 2

[Đỗ Kim Lâm]

Bây giờ mình sẽ viết đầy đủ hơn nhé:

a) \(\frac{28^{15}.3^{17}}{84^{16}}=\frac{\left(28.3\right)^{15}.3^2}{\left(28.3\right)^{15}.84}=\frac{9}{84}=\frac{3}{28}\)

b)\(\frac{3^{10}+6^2}{5.3^8+20}=\frac{3^{10}+2^2.3^2}{5.3^8+20}=\frac{3^2.\left(3^8+2^2\right)}{5.\left(3^8+2^2\right)}\)\(=\frac{9}{5}\)