Bài 1:

a) x.x.y.y.x.y.x = \(x^4.y^3\)

b) 1000.10.10= 1000. \(10^2\)

c) \(3^{15}:3^5=3^{15-5}=3^{10}\)

d) \(9^8:3=3^{16}:3=3^{15}\)

e) \(125:5^3=\dfrac{125}{5^3}=\dfrac{5^3}{5^3}=1\)

B2:

15 x 6 x 4 x 125 x 8

= (15 x 4) x (125 x 8) x 6

= 60 x 1000 x 6

= 60000 x 6

= 360000

15 x6x4x125x8

= (15x4)x6x(125x8)

= 60x6 x 1000

= 360 x 1000

= 360 000

\(x=\left(\frac{33}{5}:6-0,125\cdot8+\frac{32}{15}\cdot0,03\right)\cdot\frac{11}{4}\)

\(x=\left(\frac{33}{5}\cdot\frac{1}{6}-\frac{1}{8}\cdot8+\frac{32}{15}\cdot\frac{3}{100}\right)\cdot\frac{11}{4}\)

\(x=\left(\frac{11}{10}-1+\frac{8}{125}\right)\cdot\frac{11}{4}\)

\(x=\frac{41}{250}\cdot\frac{11}{4}\)

\(x=\frac{451}{100}\)

\(x=\left(\frac{33}{5}:6-0,125.8+\frac{32}{15}.0,03\right).\frac{11}{4}\)

\(< =>x=\left(\frac{33}{30}-1+\frac{32}{15}.\frac{3}{100}\right).\frac{11}{4}\)

\(< =>x=\left(\frac{3}{30}+\frac{32}{500}\right).\frac{11}{4}\)

\(< =>x=\left(\frac{1}{10}+\frac{8}{125}\right).\frac{11}{4}\)

\(< =>x=\frac{41}{250}.\frac{11}{4}=\frac{451}{100}\)

a)    12 : { 390 : [ 500 - ( 125 + 35. 7 ) ] }

   =  12 : { 390 : [ 500 - ( 125 + 245 ) ] }

   =   12 : { 390 : [ 500 - 370 ] }

   =   12 : { 390 : 130 }

    =   12 : 3

    =     4

b)  12000 - ( 1500 .2 + 1800 .3 + 12 . 2 : 3 )

  = 12000 - ( 3000 + 5400 + 8 )

  = 12000 - 8408

  = 3592

a)125 : x = 2² - (-1)

125 : x = 4 + 1

125 : x = 5

x = 125 : 5

x = 25

-------------------------------------------------

b) 2x - 8 = -4

2x = (-4) + 8

2x = 4

x = 4 : 2 

x = 2

-----------------------------------------------------------

c) Xem lại đề.

\(125:x=2^2-\left(-1\right)\)

\(=>125:x=4+1\)

\(=>125:x=5\)

\(=>x=125:5\)

\(=>x=25\)

_____

\(2x-8=-4\)

\(=>2x=\left(-4\right)+8\)

\(=>2x=4\)

\(=>x=4:2\)

\(=>x=2\)

_______

\(6^{2x+5}=216\)

\(=>6^{2x+5}=6^3\)

\(=>2x+5=3\)

\(=>2x=3-5\)

\(=>2x=-2\)

\(=>x=\left(-2\right):2\)

\(=>x=-1\)

\(#NqHahh\)

a, 4¹⁰. 2³⁰=2²⁰.2³⁰=2⁵⁰

b,9²⁵.27⁴.81³= 3⁵⁰.3¹².3¹²=3⁷⁴

Tương tự các câu khác....

a, 4¹⁰.2³⁰ = (2²)¹⁰.2³⁰ = 2²⁰.2³⁰ = 2⁵⁰
b, 9²⁵.27⁴.81³ = (3²)²⁵.(3³)⁴.(3⁴)³ = 3⁵⁰.3¹².3¹² = 3⁷⁴
c, 25⁵⁰.125⁵ = (5²)⁵⁰.(5³)⁵ = 5¹⁰⁰.5¹⁵ = 5¹¹⁵
d, 64³.4⁸.16⁴ = (2⁶)³.(2²)⁸.(2⁴)⁴ = 2¹⁸.2¹⁶.2¹⁶ = 2⁵⁰
e, 3⁸ : 3⁶ = 3²
2¹⁰ : 8³ = 2¹⁰ : (2³)³ = 2¹⁰ : 2⁹ = 2
12⁷ : 6⁷ = (12 : 6)⁷ = 2⁷
@Dương Tuyết Mai

1. 

x.x.y.y.x.y.x=(x.x.x.x) (y.y.y)=x⁴.y³=(x.y)^4.3=xy¹²

1000.10.10=10³.10.10=10³⁺¹⁺¹=10⁵

3¹⁵:3⁵=3^15–5=3¹⁰

9⁸:3=(3²)⁸:3=3¹⁶:3=3^16–1=3¹⁵

125:5³=5³:5³=1

DỊT MẢ CHA 

mk mới học lớp 6

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