Question

\(I\).Biểu thức

1)65.59+65.42-65

\(II\).Tìm x

1)6.(70-x)=330

2)10+2x=4⁵:4³

3)37-2(x+5)=9

\(III\).So sánh

2³³³ và 3²²²

Answer 1

I, 65.5+65.42-65=6500

II,

1,420-6x=330

<=>-6x=-90

<=>x=15

2, 10+2x=65536

<=>2x=65526

<=>x=32763

3, 37-2x-10=9

<=>-2x=-18

x=9

III, 2³³³<3²²²

Answer 2

Bài 1 .

65 . 59 - 65 . 42 - 65

= 65 . ( 59 - 42 ) - 65

= 65 . 17 - 65

= 1105 - 65

= 1040

Bài 2 .

a) 6 . ( 70 - x ) = 330

<=> 70 - x = 330 : 6

<=> 70 - x = 55

<=> x = 70 - 55

<=> x = 15

Vậy x = 15

b) 10 + 2x = 4⁵ : 4³

<=> 10 + 2x = 4²

<=> 10 + 2x = 16

<=> 2x = 16 - 10

<=> 2x = 6

<=> x = 6 : 2

<=> x = 3

Vậy x = 3.

c) 37 - 2( x + 5 ) = 9

<=> 2( x + 5 ) = 37 - 9

<=> 2( x + 5 ) = 28

<=> x + 5 = 28 : 2

<=> x + 5 = 14

<=> x = 14 - 5

<=> x = 9

Vậy x = 9.

Answer 3

Bài 3 . So sánh

2³³³ và 3²²²

Ta có : 2³³³ = ( 2³ )¹⁰⁰ = 8¹⁰⁰

3²²² = ( 3² )¹⁰⁰ = 9¹⁰⁰

Vì 8¹⁰⁰ < 9¹⁰⁰ nên 2³³³ < 3²²².

Answer 4

I Biểu thức

\(1,65.59+65.42-65\)

\(=65\left(59+42-1\right)\)

\(=65.100\)

\(=6500\)

II Tìm x

\(1,6\left(70-x\right)=330\)

\(6.70-6x=330\)

\(420-6x=330\)

\(6x=420-330\)

\(6x=90\)

\(x=\dfrac{90}{6}=15\)

Vậy \(x=15\)

\(2,10+2x=4^5:4^3\)

\(10+2x=4^2\)

\(2x=4^2-10\)

\(2x=6\)

\(x=\dfrac{6}{2}=3\)

Vậy \(x=3\)

\(3,37-2\left(x+5\right)=9\)

\(2\left(x+5\right)=37-9\)

\(2\left(x+5\right)=28\)

\(x+5=\dfrac{28}{2}=14\)

\(x=14-5=9\)

Vậy \(x=9\)

III So sánh

\(2^{333}\) và \(3^{222}\)

\(2^{333}=\left(2^3\right)^{111}=8^{111}\)

\(3^{222}=\left(3^2\right)^{111}=9^{111}\)

\(\Rightarrow8^{111}< 9^{111}\Rightarrow2^{333}< 3^{222}\)