Bài 44: (SBT/12):

a. (7.3⁵ - 3⁴ + 3⁶) : 3⁴

= (7.3⁵ : 3⁴) + (-3⁴ : 3⁴) + (3⁶ : 3⁴)

= 7 . 3 - 1 + 3²

= 21 - 1 + 9

= 29

b. (16³ - 64²) : 8³

= [(2.8)³ - (8²)² ] : 8³

= (2³ . 8³ - 8⁴) : 8³

= ( 2³ . 8³ : 8³) + (-8⁴ : 8³)

= 2³ - 8

= 8 - 8

= 0

a) \(\left(7.3^5-3^4+3^6\right):3^4\)

\(=7.3^5:3^4-3^4:3^4+3^6:3^4\)

\(=7.3^{5-4}-3^{4-4}+3^{6-4}\)

\(=7.3^1-3^0+3^2\)

\(=7.3-1+9\)

\(=21-1+9\)

\(=20+9\)

\(=29\)

b) \(\left(16^3-64^2\right):8^3\)

\(=\left[\left(2^4\right)^3-\left(2^6\right)^2\right]:\left(2^3\right)^3\)

\(=\left(2^{4.3}-2^{6.3}\right):2^{3.3}\)

\(=\left(2^{12}-2^{12}\right):2^9\)

\(=2^{12-9}-2^{12-9}\)

\(=2^3-2^3\)

\(=8-8\)

\(=0\)

a)-1-2-3-4-5-6-....-80

=(-1)+(-2)+(-3)+(-4)+(-5)+(-6)+...+(-80)

Khoảng cách giữa các số:(-1)-(-2)=1

Tổng các số hạng:(-1)-(-80)+1=80 số

Tổng:[(-1)+(-80)].80:2= -3240

=>-1-2-3-4-5-6+......-80=-3240

b,1-2+3-4+5-6+......+2021-2022

=(1-2)+(3-4)+(5-6)+...+(2021-2022)

=(-1)+(-1)+(-1)+...+(-1)

Tổng số cặp là:

(2022-1+1):2=1011 cặp

-1.1011=-1011

=>1-2+3-4+5-6+......+2021-2022= -1011

c, Đề bài sai

d,-4-8-12-16-.......-2020

=-4+(-8)+(-12)+(-16)+...+(-2020)

Khoảng cách giữa các số:-4-(-8)=4

Tổng các số hạng:[-4-(-2020]:4+1=505 số

Tổng:[-4+(-2020)].505:2=-511060

=>-4-8-12-16-.......-2020=-511060

Mọi người giúp mình với ạ! Thank you everyone!

a: \(=\dfrac{5}{9}-\dfrac{12+5}{15}:\dfrac{6}{5}\)

\(=\dfrac{5}{9}-\dfrac{17}{15}\cdot\dfrac{5}{6}=\dfrac{5}{9}-\dfrac{17}{18}=-\dfrac{7}{18}\)

b: \(=\left[\dfrac{6}{5}\left(3+\dfrac{3}{8}-6-\dfrac{5}{8}\right)\right]\cdot\dfrac{5}{6}=-3-\dfrac{1}{4}=-\dfrac{13}{4}\)

1)(7.243-81+729):81=29

2)(4096-4096):64=0

3)(9x^2.3x^2y++36y^2):3y=3x^2y+12y

Cần lắm những tấm lòng nhân ái :((

`@` `\text {Ans}`

`\downarrow`

`a.`

\(0,3-\dfrac{4}{9}\div\dfrac{4}{3}\cdot\dfrac{6}{5}+1\)

`=`\(0,3-\dfrac{1}{3}\cdot\dfrac{6}{5}+1\)

`=`\(0,3-0,4+1\)

`= -0,1 + 1`

`= 0,9`

`b.`

\(1+2\div\left(\dfrac{2}{3}-\dfrac{1}{6}\right)\cdot\left(-2,25\right)\)

`=`\(1+2\div\dfrac{1}{2}\cdot\left(-2,25\right)\)

`=`\(1+4\cdot\left(-2,25\right)\)

`= 1+ (-9) = -8`

`c.`

\(\left[\left(\dfrac{1}{4}-0,5\right)\cdot2+\dfrac{8}{3}\right]\div2\)

`=`\(\left(-\dfrac{1}{4}\cdot2+\dfrac{8}{3}\right)\div2\)

`=`\(\left(-\dfrac{1}{2}+\dfrac{8}{3}\right)\div2\)

`=`\(\dfrac{13}{6}\div2\)

`=`\(\dfrac{13}{12}\)

`d.`

\(\left[\left(\dfrac{3}{8}-\dfrac{5}{12}\right)\cdot6+\dfrac{1}{3}\right]\cdot4\)

`=`\(\left(-\dfrac{1}{24}\cdot6+\dfrac{1}{3}\right)\cdot4\)

`=`\(\left(-\dfrac{1}{4}+\dfrac{1}{3}\right)\cdot4\)

`=`\(\dfrac{1}{12}\cdot4=\dfrac{1}{3}\)

`e.`

\(\left(\dfrac{4}{5}-1\right)\div\dfrac{3}{5}-\dfrac{2}{3}\cdot0,5\)

`=`\(-\dfrac{1}{5}\div\dfrac{3}{5}-\dfrac{1}{3}\)

`=`\(-\dfrac{1}{3}-\dfrac{1}{3}=-\dfrac{2}{3}\)

`f.`

\(0,8\div\left\{0,2-7\left[\dfrac{1}{6}+\left(\dfrac{5}{21}-\dfrac{5}{14}\right)\right]\right\}\)

`=`\(0,8\div\left[0,2-7\left(\dfrac{1}{6}-\dfrac{5}{42}\right)\right]\)

`=`\(0,8\div\left(0,2-7\cdot\dfrac{1}{21}\right)\)

`=`\(0,8\div\left(0,2-\dfrac{1}{3}\right)\)

`= 0,8 \div (-2/15)`

`=-6`

`@` `yHGiangg.`

A: \(A=\sqrt{9}-3\sqrt{\dfrac{50}{9}}+3\sqrt{8}-\sqrt[3]{27}\)

\(=3-3\cdot\dfrac{5\sqrt{2}}{3}+6\sqrt{2}-3\)

\(=-5\sqrt{2}+6\sqrt{2}=\sqrt{2}\)

b: \(B=\sqrt{\left(2-\sqrt{3}\right)^2}+\dfrac{2}{\sqrt{3}-1}-6\cdot\sqrt{\dfrac{16}{3}}\)

\(=\left|2-\sqrt{3}\right|+\dfrac{2\left(\sqrt{3}+1\right)}{3-1}-6\cdot\dfrac{4}{\sqrt{3}}\)

\(=2-\sqrt{3}+\sqrt{3}+1-4\sqrt{3}\)

\(=3-4\sqrt{3}\)

\(A=\sqrt{9}-3\sqrt{\dfrac{50}{9}}+3\sqrt{8}-\sqrt[3]{27}\\ =3-3\cdot\dfrac{1}{3}\sqrt{25\cdot2}+3\sqrt{4\cdot2}-3\\ =3-1\cdot5\sqrt{2}+3\cdot2\sqrt{2}-3\\ =3-5\sqrt{2}+6\sqrt{2}-3\\ =\sqrt{2}\)

\(B=\sqrt{\left(2-\sqrt{3}\right)^2}+\dfrac{2}{\sqrt{3}-1}-6\sqrt{\dfrac{16}{3}}\\ =\left|2-\sqrt{3}\right|+\dfrac{2\left(\sqrt{3}+1\right)}{3-1}-6\cdot\dfrac{4\sqrt{3}}{3}\\ =2-\sqrt{3}+\sqrt{3}+1-8\sqrt{3}\\ =3-8\sqrt{3}\)

a) Ta có: \(A=\dfrac{2}{3}-\left(-\dfrac{5}{7}+\dfrac{2}{3}\right)\)

\(=\dfrac{2}{3}+\dfrac{5}{7}-\dfrac{2}{3}\)

\(=\dfrac{5}{7}\)

Thực hiện phép tính:

a, 5/17 + -5/34 . 2/5=5/17 + -1/17=4/17

b, 1/2 . 5/6 + 2/3 . 3/4 =5/12 + 6/12 =11/12

c, ( -2/5 + 1/3 ) . ( 3/2 - 3/7 )=-1/15 . 15/14=1/14

a) 49 - 9 . [ 3⁴ : 3¹ - ( 12 - 4 ) : 2²  ]

= 49 - 9 . [ 3³ - 8 : 2² ]

=  49 - 9 . [ 3³ -2³ : 2² ]

=  49 - 9 . [ 3³ - 2 ]

= 49 - 9 . [ 27 - 2 ]

= 49 - 9 . 25

= 49 - 225 = -176

b) 4.5² + 16 : 2²

= 4. 25 + 2⁴ : 2²

= 100 + 2² = 100+ 4 =104

--tho--là tớ💋

c) 5³ : 5 - 2017⁰

= 5² - 1 = 25 - 1= 24 

d) 2² . 3 - ( 10⁰ + 8 ) : 3²

= 4. 3 - ( 1 + 8 ) : 3²

= 4. 3 - 9 : 3²

= 12 - 3² : 3²

= 12 - 1 = 11.

--tho--là tớ💋