Bài 5B
a, 91 ³ + 3 . 91 ² . 9 + 3 . 91 . 9 ² + 9 ³
b, 1001 ³
c, 102 ³ – 6 . 102 ² + 12 . 102 – 8
Bài 5B a, 91 ³ + 3 . 91 ² . 9 + 3 . 91 . 9 ² + 9 ³ b, 1001 ³ c, 102 ³ – 6 . 102 ² + 12 . 102 – 8
By Lyla
By Lyla
Bài 5B
a, 91 ³ + 3 . 91 ² . 9 + 3 . 91 . 9 ² + 9 ³
b, 1001 ³
c, 102 ³ – 6 . 102 ² + 12 . 102 – 8
a,91 ³ + 3 . 91 ² . 9 + 3 . 91 . 9 ² + 9 ³
`=(91 + 9)^3`
`=100^3`
`=1000000`
`b, 1001 ³`
`=(1000 + 1)^3`
`=1000^(3) + 3.1000^(3).1 + 3.1000.1^(3) + 1^3`
`=1003003001`
`c, 102 ³ – 6 . 102 ² + 12 . 102 – 8`
`=102^(3) – 3.102^(2).2 + 6.102.2^(2) – 2^3`
`=(100-2)^3`
`=100^3`
`=1000000`
`#Study well`
`a) 91^3 + 3.91^{2}.9 + 3.91.9^{2} + 9^3`
`= (91 + 9)^3`
`= 100^3`
`= 1000000`
`b) 1001^3`
`= (1000 + 1)^3`
`= 1000^3 + 3.1000^{2}.1 + 3.1000.1 + 1`
`= 1003003001`
`c) 102^3 – 6.102^2 + 12.102 – 8`
`= 102^3 – 3.102^{2}.2 + 3.102.2^2 – 2^3`
`= (102 – 2)^3`
`= 100^3`
`= 1000000`