1. Tính
a) 5^7 : 5^4 – ( 3^2 – 2^3 )
b) -7/5 + 8/13 + -3/5 + 5/13
2. Tìm x
( x – 1/4 ) : 4/5 = 15/16
1. Tính a) 5^7 : 5^4 – ( 3^2 – 2^3 ) b) -7/5 + 8/13 + -3/5 + 5/13 2. Tìm x ( x – 1/4 ) : 4/5 = 15/16
By Cora
By Cora
1. Tính
a) 5^7 : 5^4 – ( 3^2 – 2^3 )
b) -7/5 + 8/13 + -3/5 + 5/13
2. Tìm x
( x – 1/4 ) : 4/5 = 15/16
1. Tính
`a) 5^7 : 5^4 – ( 3^2 – 2^3 )`
`= 5^3 – (9 – 8) `
`= 125 – 1`
`= 124`
`b) (-7/5) + 8/13 + (-3/5) + 5/13 `
`= [(-7/5) + (-3/5)] + (8/13 + 5/13)`
`= (-10/5) + 13/13`
`= -2 + 1`
`= -1`
2. Tìm x
`( x – 1/4 ) : 4/5 = 15/16`
`=> x – 1/4 = 15/16 × 4/5`
`=> x – 1/4 = 3/4`
`=> x = 3/4 + 1/4`
`=> x = 1`
(Chúc bạn học tốt)
`a) 5^7 : 5^4 – ( 3^2 – 2^3)`
`= 5^3 – ( 9 – 8)`
`= 125 – 1`
`= 124`
`b) -7/5 + 8/13 + -3/5 + 5/13`
`= (-7/5 + -3/5) + ( 8/13 + 5/13)`
`= -2 + 1`
`= -1`
2. Tìm x
`( x – 1/4 ) : 4/5 = 15/16`
`( x- 1/4) = 15/16 . 4/5`
`x – 1/4 = 3/4`
`x = 3/4 + 1/4`
`x = 1`