rút gọn phân số:
a : ( -21 ) . ( – 5 ) / 15 . ( -7 )
b : 25.13 / 26.35
c : 2^3 . 3^4 / 2^2 . 3^2 . 5
d : 2^4 . 5^2 . 11^2 . 7 / 2^3 . 5^3 . 7^2 . 11
rút gọn phân số:
a : ( -21 ) . ( – 5 ) / 15 . ( -7 )
b : 25.13 / 26.35
c : 2^3 . 3^4 / 2^2 . 3^2 . 5
d : 2^4 . 5^2 . 11^2 . 7 / 2^3 . 5^3 . 7^2 . 11
` a)[ (-21).(-5)]/[15.(-7)]`
`=[ (-3).(-1)]/[3.(-1)]`
`= 3/-3`
`= -1`
`b) (25.13) / (26.35)`
`= (5.1)/(2.7)`
`= 5/14`
`c)(2^3 . 3^) /(2^2 . 3^2 . 5)`
`=( 2.3^2)/(2.1.5)`
`= 2.9/10`
`=18/10`
`= 9/5`
`d) (2^4 . 5^2 . 11^2 . 7) / (2^3 . 5^3 . 7^2 . 11)`
`= (2 . 1 . 11 . 1) / (1 . 5 . 7 .1)`
`= 22/35`
Vote 5 sao +ctlhn