Câu 1 : Rút gọn phân số a ) 4.11/3.22 b ) 2^4.125/2^7.50 c ) 11(-135)+11.115/65-85 d 2^8.5^9-10^8/2^9.5^10 24/09/2021 Bởi Athena Câu 1 : Rút gọn phân số a ) 4.11/3.22 b ) 2^4.125/2^7.50 c ) 11(-135)+11.115/65-85 d 2^8.5^9-10^8/2^9.5^10
`a) \frac{4.11}{3.22} = \frac{4.1}{3.2} = 4/6 = 2/3` ` b) \frac{ 2^4 . 125}{2^7 . 50} = \frac{ 1 . 5^3}{2^4 . 5^2} = 5/16` `c) \frac{ 11( -135 ) + 11 . 115}{65 – 85 } = \frac{ 11( -135 + 115)}{ 5 . 13 – 5 . 17} = \frac{ 11 . (-20)}{5 . ( -4 )} = 11` `d) \frac{ 2^8 . 5^9 – 10^8}{ 2^9 . 5^{10}} = \frac{ 2^8 . 5^9 – 2^8 . 5^8 }{2^9 . 5^{10}} = \frac{2^8 . 5^8( 5 – 1 )}{ 2^9 . 5^{10}} = \frac{2^{10} . 5^8}{2^9 . 5^{10}} = \frac{2.1}{5^2} = 2/25` Bình luận
`a) \frac{4.11}{3.22} = \frac{4.1}{3.2} = 4/6 = 2/3`
` b) \frac{ 2^4 . 125}{2^7 . 50} = \frac{ 1 . 5^3}{2^4 . 5^2} = 5/16`
`c) \frac{ 11( -135 ) + 11 . 115}{65 – 85 } = \frac{ 11( -135 + 115)}{ 5 . 13 – 5 . 17} = \frac{ 11 . (-20)}{5 . ( -4 )} = 11`
`d) \frac{ 2^8 . 5^9 – 10^8}{ 2^9 . 5^{10}} = \frac{ 2^8 . 5^9 – 2^8 . 5^8 }{2^9 . 5^{10}} = \frac{2^8 . 5^8( 5 – 1 )}{ 2^9 . 5^{10}} = \frac{2^{10} . 5^8}{2^9 . 5^{10}} = \frac{2.1}{5^2} = 2/25`