2/5 x 1/x + 1/x x 2 + 2/5 = 1/2

1/x x ( 2/5 + 2 ) + 2/5 = 1/2

1/x x 6/5 + 2/5 = 1/2

1/x x 6/5 = 1/2 - 2/3

( 1 : x) x 6/5 = -1/6

1:x = -1/6 : 6/5

1: x = -5/36

⇔ x =  -36/5.

Vậy x = -36/5.

giúp tớ với ah tớ cần gấp

`10x =8x+12`

`=>10x-8x=12`

`=>(10-8)x=12`

`=>2x=12`

`=>x=12:2`

`=>x=6`

Vậy `x=6`

`@` `\text {Ans}`

`\downarrow`

`10*x = 8*x + 12`

`=> 10x - 8x - 12 = 0`

`=> (10 - 8)x - 12 = 0`

`=> 2x = 0+12`

`=> 2x = 12`

`=> x = 12 \div 2`

`=> x = 6`

Vậy, `x=6.`

giups mik nhanh voi ak

\(A=1+4^2+4^4+...+4^{2000}\)

\(\Rightarrow4^2A=4^2+4^4+4^6+...+4^{2000}+4^{2002}\)

\(\Rightarrow16A-A=\left(4^2+4^4+4^6+...+4^{2002}\right)-\left(1+4^2+4^4+....+4^{2000}\right)\)

\(\Rightarrow15A=\left(4^2-4^2\right)+\left(4^4-4^4\right)+...+\left(4^{2000}-4^{2000}\right)+\left(4^{2002}-1\right)\)

\(\Rightarrow15A=0+0+0+...+4^{2002}-1\)

\(\Rightarrow15A=4^{2002}-1\)

\(\Rightarrow A=\dfrac{4^{2002}-1}{15}\)

3/7 + 1/2 - 17/7 +3/2

=(1/2+3/2) + (3/7-17/7)

=2+-2

=0

phép tính gì em?

5³ = 5 x 5 x 5 = 25 x 5 = 125

2⁷ = 2 x 2 x 2 x 2 x 2 x 2 x 2= 4 x 2 x 2 x 2 x2 x2

= 8 x 2 x 2 x 2 x2 = 16 x 2 x 2 x 2= 32 x 2 x 2 = 64 x 2 = 128

ủa có yc đề là nhân hở ta

`@` `\text {Ans}`

`\downarrow`

`a)`

\(24 \div a+24=30\)

`=> 24 \div a = 30 - 24`

`=> 24 \div a = 6`

`=> a = 24 \div 6`

`=> a = 4`

Vậy, `a=4`

`b)`

\( 1974 \div 14+a \times 141=423\)

`=> 141 + a \times 141 = 423`

`=> a \times 141 = 423 - 141`

`=> a \times 141 = 282`

`=> a = 282 \div 141`

`=> a = 2`

Vậy, `a=2`

`c)`

\(120-(45-a \times 4)=115\)

`=> 45 - a \times 4 = 120 - 115`

`=> 45 - a \times 4 = 5`

`=> a \times 4 = 45 - 5`

`=> a \times 4 = 40`

`=> a = 40 \div 4`

`=> a = 10`

Vậy, `a=10`

`d)`

\((a \times 4-44) \div 4=44\)

`=> a \times 4 - 44 = 44 \times 4`

`=> a \times 4 - 44 = 176`

`=> a \times 4 = 176 + 44`

`=> a \times 4 = 220`

`=> a = 220 \div 4`

`=> a = 55`

Vậy, `a = 55.`

a) 24:a+24=30

 24:a= 30 - 24

24:a=6

a= 24:6

a=4

______

b) 1974:14+ax141=423 

141 + a x 141 = 423

141 x (a+1) = 423

a+1 = 423 : 141

a+1=3

a=3-1

a=2

_____
c) 120-(45-ax4)=115

45 - a x 4= 120 - 115

45 - a x 4= 5

a x 4 = 45 - 5

a x 4 = 40

a = 40:4

a=10

______

  d) (ax4-44):4=44

a x 4 - 44 = 44  x 4

a x 4 - 44 = 176

a x 4 = 176 + 44

a x 4 = 220

a= 220:4

a=55

\(324\cdot36-254\cdot72+18\cdot368\)

\(=18\cdot\left(324\cdot2-254\cdot3+368\right)\)

\(=18\cdot\left(648-1016+368\right)\)

\(=18\cdot\left(1016-1016\right)\)

\(=18\cdot0\)

\(=0\)

\(7364-\left(8475-4555\right)-364+445+475\)

\(=7364-8475+4555-364+445+475\)

\(=\left(7364-364\right)-\left(8475-475\right)+\left(4555+445\right)\)

\(=7000-8000+5000\)

\(=4000\)

\(21\cdot32\cdot43-21\cdot32\cdot40-21\cdot32\cdot3\)

\(=21\cdot32\cdot\left(43-40-3\right)\)

\(=21\cdot32\cdot0\)

\(=21\cdot0\)

\(=0\)

*Note: Tích của một số với 0 luôn bằng 0.

a) \(\left(1763+7634+23\cdot764\right)\cdot\left(346\cdot45-173\cdot90\right)\)

\(=\left(1763+7634+23\cdot764\right)\cdot\left(346\cdot45-173\cdot45\cdot2\right)\)

\(=\left(1763+7634+23\cdot764\right)\cdot\left(346\cdot45-346\cdot45\right)\)

\(=\left(1763+7634+23\cdot764\right)\cdot0\)

\(=0\)

b) \(N=10\cdot12\cdot14\cdot16\cdot\left(88\cdot17-44\cdot34\right)\)

\(N=10\cdot12\cdot14\cdot16\cdot\left(88\cdot17-44\cdot17\cdot2\right)\)

\(N=10\cdot12\cdot14\cdot16\cdot\left(88\cdot17-88\cdot17\right)\)

\(N=10\cdot12\cdot14\cdot16\cdot0\)

\(N=0\)

c) \(\left(80\cdot96+40\cdot1808\right):1000\)

\(=\left(80\cdot96+40\cdot904\cdot2\right):1000\)

\(=\left(80\cdot96+80\cdot904\right):1000\)

\(=\left[80\cdot\left(96+904\right)\right]:1000\)

\(=80\cdot1000:1000\)

\(=80\)