a, ĐK: \(x\ne24\)

580 :( x -24 ) =329 -150 : 2

<=> 580 :( x -24 ) = 329 - 75

<=> 580 :( x -24 ) = 254

<=> x - 24 = \(\frac{290}{127}\)

<=> x = \(\frac{3338}{127}\left(TM\right)\)

Vậy \(x=\frac{3338}{127}\)

b, 7 (x-1 ) +35= 25 + 279 :9

<=> 7x - 7 + 35 = 25 + 31

<=> 7x +28 = 56

<=> 7x = 28

<=> x = 4

Vậy x =4

c,4 ( 2x+ 7 ) -3 (3x -2 ) =24

<=> 8x + 28 - 9x + 6 = 24

<=> 34 - x = 24

<=> x = 10

Vậy x = 10

d,( x-1 ) (x-2) =3(x-1)

<=> ( x-1 ) (x-2) - 3(x-1) = 0

<=> (x- 1)(x - 2 - 3) = 0

<=> (x -1)(x - 5) = 0

<=> \(\left[{}\begin{matrix}x-1=0\\x-5=0\end{matrix}\right.\) <=> \(\left[{}\begin{matrix}x=1\\x=5\end{matrix}\right.\)

Vậy x ={1; 5}

e, (x + 3) + (x + 7) + (x + 11) + ... + (x + 79) = 860

x + 3 + x + 7 + x + 11 + ... + x + 79 = 860

Có tất cả: (79 - 3) : 4 + 1 = 20 số hạng \(\Rightarrow\) có 20x

hay x + 3 + x + 7 + x + 11 + ... + x + 79 = 860

\(\Rightarrow\) 20x + (3 + 7 + ... + 79) = 860

3 + 7 + ... + 79 = (79 + 3) x 20 : 2 = 820

\(\Rightarrow\) 20x + (3 + 7 + ... + 79) = 860

\(\Rightarrow\) 20x + 820 = 860

\(\Rightarrow\) 20x = 40

\(\Rightarrow\) x = 2

Vậy x = 2

Chúc bn học tốt!

1/ -7264 + (1543 + 7264)
=-7264 + 1543 + 7264=1543
2/ (144 – 97) – 144

=144-97-144=-97

3/ (-145) – (18 – 145)(Vì có dấu trừ ở trước ngoặc nên p đổi dấu)

=-145-18+145=-18

4/ 111 + (-11 + 27)

=111-11+27=137

1/ -7264 + (1543 + 7264)
=-7264 + 1543 + 7264=1543
2/ (144 – 97) – 144
=144-97-144=-97
3/ (-145) – (18 – 145)(Vì có dấu trừ ở trước ngoặc nên p đổi dấu)
=-145-18+145=-18
4/ 111 + (-11 + 27)
=111-11+27=137

Sao giống y chang chương trình của mình vậy :)

2⁴.x-3².x=145-255:51

16.x-9.x=145-5

16.x-9.x=140

x.(16-9)=140

x.7=140

x=140:7

x=20

580:(x-24)=329-150:2=ko bít

7.(x-4)+35=25+279:9

7.(x-4)+35=25+31

7.(x-4)+35=56

7.(x-4)=56-35

7.(x-4)=21

x-4=21:7

x-4=3

x=3+4

x=7

Ủng hộ nha!

*) Tính:

a) 105

b) 73

c) 40

d) 27

e) 511

a)7x+2x=918;           

9x=918

x=102.

Vay x=102.

a) Ta có: \(\left(x-3\right)=\left(3-x\right)^2\)

\(\Leftrightarrow\left(x-3\right)^2-\left(x-3\right)=0\)

\(\Leftrightarrow\left(x-3\right)\left(x-4\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=3\\x=4\end{matrix}\right.\)

b) Ta có: \(x^3+\dfrac{3}{2}x^2+\dfrac{3}{4}x+\dfrac{1}{8}=\dfrac{1}{64}\)

\(\Leftrightarrow x^3+3\cdot x^2\cdot\dfrac{1}{2}+3\cdot x\cdot\dfrac{1}{4}+\left(\dfrac{1}{2}\right)^3=\dfrac{1}{64}\)

\(\Leftrightarrow\left(x+\dfrac{1}{2}\right)^3=\left(\dfrac{1}{4}\right)^3\)

\(\Leftrightarrow x+\dfrac{1}{2}=\dfrac{1}{4}\)

hay \(x=-\dfrac{1}{4}\)

c) Ta có: \(8x^3-50x=0\)

\(\Leftrightarrow2x\left(4x^2-25\right)=0\)

\(\Leftrightarrow x\left(2x-5\right)\left(2x+5\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x=\dfrac{5}{2}\\x=-\dfrac{5}{2}\end{matrix}\right.\)

e) Ta có: \(x\left(x+3\right)-x^2-3x=0\)

\(\Leftrightarrow\left(x+3\right)\left(x-1\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=-3\\x=1\end{matrix}\right.\)

f) Ta có: \(x^3+27+\left(x+3\right)\left(x-9\right)=0\)

\(\Leftrightarrow\left(x+3\right)\left(x^2-3x+9\right)+\left(x+3\right)\left(x-9\right)=0\)

\(\Leftrightarrow\left(x+3\right)\left(x^2-2x\right)=0\)

\(\Leftrightarrow x\left(x-2\right)\left(x+3\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x=2\\x=-3\end{matrix}\right.\)

Bài 2:

a: Ta có: \(2x+79=x+45\)

nên 2x-x=45-79

hay x=-24

b: Ta có: \(15-\left(x+7\right)=\left(x-8\right)+22\)

\(\Leftrightarrow8-x-x-14=0\)

\(\Leftrightarrow2x=22\)

hay x=11

a) \(2^4.x-3^2.x=145-\frac{255}{51}\Rightarrow x.\left(2^4-3^2\right)=145-5\)

\(\Rightarrow7.x=140\Rightarrow x=20\)

b) \(\frac{580}{x-24}=329-150.2\Rightarrow\frac{580}{x-24}=329-300\Rightarrow\frac{580}{x-24}=29\Rightarrow x-24=20\)

\(\Rightarrow x=44\)

c) \(7.\left(x-14\right)+35=25+\frac{279}{9}\Rightarrow7.\left(x-14\right)=25+31-35\)

\(\Rightarrow7.\left(x-14\right)=21\Rightarrow x-14=3\Rightarrow x=17\)

a) (25x32) : 8           

= 25 x (4 x 8) : 8

= (25 x 4) x (8:8)

= 100 x 1

=100

b, 24 x 11 + 6 x 86 x 4 + 72

= 24 x 11 + (6 x 4) x 86 + 24 x 3

= 24 x 11 + 24 x 86 + 24 x 3

= 24 x (11+86+3)

= 24 x 100

= 2 400

\(\left(25\times32\right):8=25\times32:8=25\times\left(32:8\right)=25\times4=100\\ 24\times11+6\times86\times4+72\\ =24\times11+24\times86+24\times3\\ =24\times\left(11+86+3\right)\\ =24\times100=2400\\ 36\times5+9\times79\times4+72\times8\\ =36\times5+36\times79+36\times16\\ =36\times\left(5+79+16\right)\\ =36\times100=3600\\ \left(56\times125\right):7=56\times125:7=\left(56:7\right)\times125=8\times125=1000\)