a) \(\left(19x+2\cdot5^2\right)\div14=\left(13-8\right)^2-4^2\)

\(\left(19x+2\cdot25\right)\div14=5^2-16\)

\(\left(19x+50\right)\div14=25-16=9\)

\(19x+50=9\cdot14=126\)

\(19x=126-50=76\)

\(x=76\div19=4\)

b) \(2\cdot3^x=10\cdot3^{12}+8\cdot\left(3^3\right)^4\)

\(2\cdot3^x=\left(10+8\right)\cdot3^{12}\)

\(2\cdot3^x=18\cdot3^{12}\)

\(\Rightarrow2\cdot3^x=2\cdot3^2\cdot3^{12}\Rightarrow2\cdot3^x=2\cdot3^{15}\Rightarrow x=15\)

a, \left(19.x+2.5^2\right)\div14=\left(13-8\right)^2-4^2(19.x+2.52)÷14=(13−8)2−42
\left(19.x+2.25\right)\div14=5^2-4^2(19.x+2.25)÷14=52−42
\left(19.x+2.25\right)\div14=25-16(19.x+2.25)÷14=25−16
\left(19.x+50\right)\div14=9(19.x+50)÷14=9
\left(19.x+50\right)=9.14(19.x+50)=9.14
19.x+50=12619.x+50=126
19.x=126-5019.x=126−50
19.x=7619.x=76
\Rightarrow x=76\div19⇒x=76÷19
\Rightarrow x=4⇒x=4
Vậy x = 4
b, 2.3^x=10.3^{12}+8.27^42.3x=10.312+8.274
2.3^x=10.3^{12}+8.\left(3^3\right)^42.3x=10.312+8.(33)4
2.3^x=10.3^{12}+8.3^{12}2.3x=10.312+8.312
2.3^x=\left(10+8\right).3^{12}2.3x=(10+8).312
2.3^x=18.3^{12}2.3x=18.312
2.3^x=2.3^3.3^{12}2.3x=2.33.312
2.3^x=2.3^{15}2.3x=2.315
\Rightarrow x=15⇒x=15
Vậy x = 15

a.(19x+2×25):14=5^2-16 (19x+50):14=25-16 (19x+50):14=9 (19x+50)=9×14=126 19x+50=126 19x=126-50=76 x=76:19 x=4 b.2×3^x=10×3^12+2^3×3^12 2×3^x=3^12×(10+8) 2×3^x=3^12×18 2×3^x=3^12×3^2×2 2×3^x=3^14×2 Suy ra:3^x=3^14 Hay x=14

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

\(\Rightarrow x+2-2=0\)

\(\Rightarrow x=0\)

\(\left(x+3\right)+1=7\)

\(\Rightarrow x+3+1=7\)

\(\Rightarrow x+4=7\)

\(\Rightarrow x=3\)

\(\left(3x-4\right)+4=12\)
\(\Rightarrow3x-4+4=12\)

\(\Rightarrow3x=12\)

\(\Rightarrow x=4\)

\(\left(5x+4\right)-1=13\)

\(\Rightarrow5x+4-1=13\)

\(\Rightarrow5x+3=13\)

\(\Rightarrow5x=10\)

\(\Rightarrow x=2\)

\(\left(4x-8\right)-3=5\)

\(\Rightarrow4x-8-3=5\)

\(\Rightarrow4x-11=5\)

\(\Rightarrow4x=16\)

\(\Rightarrow x=4\)

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

\(\Rightarrow8-2x-4=2\)

\(\Rightarrow4-2x=2\)

\(\Rightarrow2x=2\)

\(\Rightarrow x=1\)

\(7+\left(5x+2\right)=14\)

\(\Rightarrow7+5x+2=14\)

\(\Rightarrow9+5x=14\)

\(\Rightarrow5x=5\)

\(\Rightarrow x=1\)

\(5-\left(3x-11\right)=1\)

\(\Rightarrow5-3x+11=1\)

\(\Rightarrow16-3x=1\)

\(\Rightarrow3x=15\)

\(\Rightarrow x=5\)

a) \(\left(19x+2\times5^2\right):14=\left(13-8\right)^2-4^2\)

\(\Rightarrow\left(19x+50\right):14=5^2-4^2=25-16=9\)

\(\Rightarrow19x+50=126\)

\(\Rightarrow19x=76\Rightarrow x=4\)

Vậy x = 4

b) \(2\times3^2=10\times3^{12}+8\times27^4\)

\(\Rightarrow2\times3^2=10\times\left(3^3\right)^4+8\times27^4\)

\(\Rightarrow2\times3^2=27^4\times\left(10+8\right)\)

\(\Rightarrow18=27^4\times18\)

\(\Rightarrow27^4\times18-18=0\Rightarrow18\times\left(27^4-1\right)=0\)

=> Không thấy biến x đâu cả

c) Ta thấy 3³ = 27

\(\Rightarrow3^{2x-5}=3^3\Rightarrow2x-5=3\Rightarrow2x=8\Rightarrow x=4\)

Vậy x = 4

d) \(3^{x+1}-x=80\Rightarrow3^{x+1}=81\)

Ta thấy 3⁴ = 81

\(\Rightarrow3^{x+1}=3^4\Rightarrow x+1=4\Rightarrow x=3\)

Vậy x = 3

`Answer:`

a. \(x+12=3\Leftrightarrow x=3-12\Leftrightarrow x=-9\)

b. \(2x-15=21\Leftrightarrow2x=21+15\Leftrightarrow2x=36\Leftrightarrow x=36:2\Leftrightarrow x=18\)

c. \(13-3x=4\Leftrightarrow-3x=4-13\Leftrightarrow-3x=-9\Leftrightarrow x=-9:-3\Leftrightarrow x=3\)

d. \(2\left(x-2\right)+4=12\Leftrightarrow2x-4+4=12\Leftrightarrow2x=12\Leftrightarrow x=12:2\Leftrightarrow x=6\)

e. \(15-3\left(x-2\right)=21\Leftrightarrow15-3x+6=21\Leftrightarrow-3x=21-15-6\Leftrightarrow-3x=0\Leftrightarrow x=0\)

g. \(25+4\left(3-x\right)=1\Leftrightarrow25+12-4x=1\Leftrightarrow37-4x=1\Leftrightarrow-4x=-36\Leftrightarrow x=9\)

h. \(3x+12=2x-4\Leftrightarrow3x-2x=-4-12\Leftrightarrow x=-16\)

i. \(14-3x=\left(-x\right)+4\Leftrightarrow-3x+x=4-14\Leftrightarrow-2x=10\Leftrightarrow x=5\)

k. \(2\left(x-2\right)+7=x-25\Leftrightarrow2x-4+7=x-25\Leftrightarrow2x-x=-25-3\Leftrightarrow x=-28\)

13 sao trừ được 18 bạn xem có sai đề ko 

nếu sai đề gửi đề mới mình giải cho

a, ( 19X + 2 x 5² ) : 14 = ( 13 - 18 )² - 4²

( 19X + 2 x 5² ) : 14 = ( -5 )² - 4²

( 19X + 2 x 5² ) : 14 =  25  - 16

( 19X + 2 x 25 ) : 14 =  9

( 19X + 2 x 25 )  =  9 . 14

 19X + 2 x 25   = 126

19X  +  50     = 126

19X  = 126  - 50

19X  =  76

X     =  76 : 19  = 4

b, 2 x 3^X = 10 x 3¹² + 8 x 27⁴

2 x 3^X = 10 . 531441 + 8 . 531441

2 x 3^X = 2 x 3^X = 531441( 10+8)

2 x 3^X = 531441 . 18 = 9565938

  3^x    = 9565938 : 2  = 4782969

ma  3^( dungf mt ra tips keets quar )

Hok tot

13-18=-5

thì phải 

đúng k nhé

Cau a sai de

ừ mình nhầm

a,(19x+2*5^2)/14=(13-8)^2-4^2