Question

[Phạm Duy Lộc]

Tính biểu thức sau(không có thuận tiện):

12 + 3 . 3⁵ : 4 - 3

90³ - 88 . 3 . 3⁹ . 3

10² + 10³ + 10⁴ + 10⁵ + 10⁶

7 - 3 : 2 . 7¹⁰

Answer 1

[HT.Phong (9A5)]

\(12+3\cdot3^5:4-3\)

\(=4\cdot3+3^6\cdot\dfrac{1}{4}-3\)

\(=3\cdot\left(4+3^5\cdot\dfrac{1}{4}-1\right)\)

\(=3\cdot\left(3+3^5\cdot\dfrac{1}{4}\right)\)

\(=3\cdot3\cdot\left(1+3^4\cdot\dfrac{1}{4}\right)\)

\(=9\cdot\dfrac{85}{4}\)

\(=\dfrac{785}{4}\)

_________________

\(90^3-88\cdot3\cdot3^9\cdot3\)

\(=9^3\cdot10^3-88\cdot3^{11}\)

\(=\left(3^2\right)^3\cdot10^3-88\cdot3^{11}\)

\(=3^6\cdot1000-88\cdot3^{11}\)

\(=3^6\cdot\left(1000-88\cdot3^5\right)\)

\(=3^6\cdot-20384\)

\(=-14859936\)

________________

\(10^2+10^3+10^4+10^5+10^6\)

\(=\left(10^2+10^3\right)+\left(10^4+10^5\right)+10^6\)

\(=10^2\cdot\left(1+10\right)+10^4\cdot\left(1+10\right)+10^6\)

\(=11\cdot\left(10^2+10^4\right)+10^6\)

\(=11\cdot\left(100+10000\right)+10^6\)

\(=11\cdot10100+1000000\)

\(=111100+1000000\)

\(=1111100\)

_______________

\(7-3:2\cdot7^{10}\)

\(=7\cdot\left(1-\dfrac{3}{2}\cdot7^9\right)\)

\(=7\cdot-60530409,5\)

\(=-423712866,5\)