2 bọn ngu dễ thế này ko cx ko xong

[2.(70-x)+72]:2=46

<=>2.(70-x)+72=92

<=>2(70-x)=20

<=>70-x=10

<=>x=60

[2.(70-x)+72]:2=46

=>2.(70-x)+72=46.2

=>(70-x)+72=46

=>70-x=46-72

=>70-x=-26

=>x=70-(-26)

=>x=70+26

=>x=96

\(\left[2\times\left(70-x\right)+72\right]\div2=46\)

\(\Rightarrow\left[2\times\left(70-x\right)+72\right]=46\times2\)

\(\Rightarrow\left[2\times\left(70-x\right)+72\right]=92\)

\(\Rightarrow2\times\left(70-x\right)=92-72\)

\(\Rightarrow2\times\left(70-x\right)=20\)

\(\Rightarrow\left(70-x\right)=20\div2\)

\(\Rightarrow\left(70-x\right)=10\)

\(\Rightarrow x=70-10\)

\(\Rightarrow x=60\)

[ 2. ( 70 - x ) + 72 ]: 2 =46

2. ( 70 - x ) + 72 = 46.2

2. ( 70 - x ) + 72 = 92

2. ( 70 - x ) =92-72

2. ( 70 - x ) =20

70-x=20:2

70-x=10

x=70-10

x=60

[ ( 2.x + 54 ) - 32 ] . 2 = 244 

 ( 2.x + 54 ) - 32 = 244:2

( 2.x + 54 ) - 32 = 122

2.x + 54 = 122+32

2.x + 54 = 154

2.x =154-54

2x=100

x=100:2

x=50

a, ((2.x+54)-32).2=244

((2.x+54)-32)=244:2

((2.x+54)-32)=122

(2.x+54)=122+32

(2.x+54)=154

x+54=154:2

x+54=77

x=77-54

x=23

{(2x+54)-32}.2=244

(2x+54)-32=244:2122

2x+54=154

2x=100

x=50

{2.(70-x)+72}:2=46

2.(70-x)+72=92

2(70-x)=20

70-x=10

x=60

\(\left[3.\left(70-x\right)+5\right]:2=46\)

=>   \(3.\left(70-x\right)+5=92\)

=>   \(3.\left(70-x\right)=87\)

=>   \(70-x=29\)

=>   \(x=41\)

[ 3 . ( 70 - x )+ 5 ]: 2 = 46

[ 3 . ( 70 - x )+ 5 ]     = 46 . 2

[ 3 . ( 70 - x )+ 5 ]     =  92

 3 . ( 70 - x )              = 92 - 5 

 3 . ( 70 - x )              = 87 : 3

       70 - x                 =   29

              x                 =  70 - 29

              x                 =   41

  # CHUC BAN HOK TOT

\(\left[3.\left(70-x\right)+5\right]:2=46\)

\(\Rightarrow\left[3.\left(70-x\right)+5\right]=46.2=92\)

\(\Rightarrow3\left(70-x\right)=92-5=87\)

\(\Rightarrow70-x=73:3=29\)

\(\Rightarrow x=70-29=41\)

Vậy x = 41

Chúc em học tốt nhé!

1) \(78+22+18=100+18=118.\)

2) \(94+563+\left(106-563\right)-\left(-70\right)=94+563+106-563+70\)

\(=\left(94+106\right)+\left(563-563\right)+70=270.\)

3) \(25.154-25+47.25=25.\left(154-1+47\right)=25.200=5000.\)

1: Ta có: \(\left|x^2-72\right|-2=70\)

\(\Leftrightarrow\left|x^2-72\right|=72\)

\(\Leftrightarrow\left[{}\begin{matrix}x^2-72=72\\x^2-72=-72\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x^2=144\\x^2=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=12\\x=-12\\x=0\end{matrix}\right.\)

Vậy: S={0;-12;12}

2: Ta có: \(x^2-5\left|x\right|=14\)

\(\Leftrightarrow5\left|x\right|=x^2-14\)(*)

Trường hợp 1: x≥0

(*)\(\Leftrightarrow5x=x^2-14\)

\(\Leftrightarrow x^2-14=5x\)

\(\Leftrightarrow x^2-5x-14=0\)

\(\Leftrightarrow x^2-7x+2x-14=0\)

\(\Leftrightarrow x\left(x-7\right)+2\left(x-7\right)=0\)

\(\Leftrightarrow\left(x-7\right)\left(x+2\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x-7=0\\x+2=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=7\left(nhận\right)\\x=-2\left(loại\right)\end{matrix}\right.\)

Trường hợp 2: x<0

(*)\(\Leftrightarrow-5x=x^2-14\)

\(\Leftrightarrow x^2+5x-14=0\)

\(\Leftrightarrow x^2+7x-2x-14=0\)

\(\Leftrightarrow x\left(x+7\right)-2\left(x+7\right)=0\)

\(\Leftrightarrow\left(x+7\right)\left(x-2\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x+7=0\\x-2=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-7\left(nhận\right)\\x=2\left(loại\right)\end{matrix}\right.\)

Vậy: S={-7;7}

\(a,96-3\left(x+8\right)=42\\ \Rightarrow3\left(x+8\right)=54\\ \Rightarrow x+8=18\\ \Rightarrow x=10.\\ b,15.5\left(x-25\right)-225=0\\ \Rightarrow75\left(x-25\right)-225=0\\ \Rightarrow75\left(x-25\right)=225\\ \Rightarrow x-25=3\\ \Rightarrow x=28.\\ c,250:x+15=25\\ \Rightarrow250:x=10\\ \Rightarrow x=25\\ d,36:\left(x-5\right)=2^2\\ \Rightarrow36:\left(x-5\right)=4\\ \Rightarrow x-5=9\\ \Rightarrow x=14.\\ e,\left[3.\left(70-x\right)+5\right]:2=46\\ \Rightarrow3.\left(70-x\right)+5=92\\ \Rightarrow3\left(70-x\right)=87\\ \Rightarrow70-x=29\\ \Rightarrow x=41.\)

2.

a, x-13=-46

=>x=(-46)+13

=>x=33

b, 4x-6=22

=>4x=22+6

=>4x=28

=>x=28:4

=>x=7

3.

a, 32=2⁵

48=2⁴.3

=>ƯCLN(32,48)=2⁴=16

16=2⁴

72=2³.3²

=>ƯCLN(16,72)=2³=8

b,

24=2³.3

60=2².3.5

=>BCNN(24,60)=2³.3.5=120

72=2³.3²

180=2².3².5

=>BCNN(72,180)=2³.3².5=360

a) x - 13  =  -   46 

    x         =  - ( 46 + 13 )                                

    x         =  - 59   

Chắc vậy

2a/ -33

2b/  7

3a/ 16

       8

3b/ 120

       360