Question

Tính gá trị biểu thức 

\(\frac{45^{10}.5^{20}}{75^{15}}\)

Answer 1

\(\frac{45^{10}.5^{20}}{75^{15}}=\frac{\left(5.3^2\right)^{10}.5^{20}}{\left(3.5^2\right)^{15}}=\frac{5^{10}.3^{20}.5^{20}}{3^{15}.5^{30}}=\frac{5^{30}.3^{20}}{3^{15}.5^{30}}=\frac{3^5}{1}=3^5=243\)

Answer 2

Ta có: 45¹⁰.5²⁰=(3².5)¹⁰.(5²)¹⁰

                      =3²⁰.(5²)⁵.25¹⁰

                     =3¹⁵.3⁵.25⁵.25¹⁰

                     =3⁵(3¹⁵.25¹⁵)

                     =3⁵.75¹⁵

Do đó:  \(\frac{45^{10}.5^{20}}{75^{15}}=\frac{3^5.75^{15}}{7^{15}}=3^5\)