a) x-28:7=16

    x-4=16

    x=16+4

    x=20

Vậy x=20

b)3x-63=9³⁰:9²⁸

   3(x-21)=81

   x-21=27

   x=21+27

  x=48

Vậy x=48

a, x-28:7=16

x-4=16

x=16+4

x=20

b, 3x-63=9^30:9^28

3x-63=9^2

3x-63=81

3x=81+63

3x=144

x=144:3

x=48

a: x:(-9)=-54

=>\(x=\left(-54\right)\cdot\left(-9\right)\)

=>\(x=54\cdot9=486\)

b: \(x:\left(-12\right)=18\)

=>\(x=18\cdot\left(-12\right)=-216\)

c: \(x:\left(-5\right)=-19\)

=>\(x:5=19\)

=>\(x=19\cdot5=95\)

d: \(\left(x-28\right):\left(-12\right)=-5\)

=>\(x-28=\left(-12\right)\cdot\left(-5\right)=60\)

=>x=60+28=88

e: \(\left(x+15\right):\left(-28\right)=8\)

=>x+15=-28*8=-224

=>x=-224-15=-239

f: (x+30):(-45)=-4

=>\(x+30=\left(-45\right)\cdot\left(-4\right)=180\)

=>x=180-30

=>x=150

a) x : (-9) = -54

x= -54 . (-9)= 486

________

b) x : (-12) = 18

x= 18. (-12)= -216

_________

c) x : (-5) = -19

x= (-19). (-5)= 95

__________

d) (x - 28) : (-12) = -5

(x-28)= (-5). (-12)= 60

x= 60+28= 88

_______

e) (x + 15) : (-28) = 8

(x+15)= 8. (-28)= -224

x= -224 - 15 = - 239

__________

f) (x + 30) : (-45) = -4

(x+30)= -4. (-45)= 180

x= 180 - 30=150

a) (y - 24) : 28 = 20

y - 24 = 20 x 28

y - 24 = 560 

y = 560 + 24 

y = 584

vậy y = ...

a. 

\(\left(y-24\right):28=20\)

\(\left(y-24\right)=560\)

\(y=584\)

b. \(13\times\left(y-6\right)=4\times y-6\)

\(13\times y-78=4\times y-6\)

\(9\times y=72\)
\(y=8\)
c.\(y\times3+y\times4+y:3+y:4=182\)

\(y\times\left(3+4\right)+y:\left(3+4\right)=182\)

\(y\times\left(7+\dfrac{1}{7}\right)=182\)

\(y=\dfrac{637}{25}\)

a: =>x+28=0

=>x=-28

b: =>27-x=0 hoặc x+9=0

=>x=27 hoặc x=-9

c: =>x=0 hoặc x-43=0

=>x=0 hoặc x=43

A

A

A

a: Ta có: \(\left(x^2+2\right)\left(x-4\right)-\left(x+2\right)^3=-16\)

\(\Leftrightarrow x^3-4x^2+2x-8-x^3-6x^2-12x-8=-16\)

\(\Leftrightarrow-10x^2-10x=0\)

\(\Leftrightarrow-10x\left(x+1\right)=0\)

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

c: Ta có: \(x^3+3x^2+3x+28=0\)

\(\Leftrightarrow\left(x+1\right)^3=-27\)

\(\Leftrightarrow x+1=-3\)

hay x=-4

\(a,\Rightarrow\left(4x-1\right)^2=25=5^2=\left(-5\right)^2\\ \Rightarrow\left[{}\begin{matrix}4x-1=5\\4x-1=-5\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=\dfrac{3}{2}\\x=-1\end{matrix}\right.\\ b,\Rightarrow2^x\left(1+2^3\right)=144\\ \Rightarrow2^x=144:9=16=2^4\Rightarrow x=4\\ c,\Rightarrow3^{2x+3}=3^{2\left(x+3\right)}\\ \Rightarrow2x+3=2x+6\Rightarrow0x=3\left(vô.lí\right)\\ \Rightarrow x\in\varnothing\)

a: =>7x=42

hay x=6

b: =>5x=35

hay x=7

c: =>x-14=16

hay x=30

d: =>36-4x=4

=>4x=32

hay x=8

e: =>x-12=144

hay x=156

f: =>3x-16=14

hay x=10

g: =>x+33=45

hay x=12

h: =>(x+9):2=39

=>x+9=78

hay x=69

a: =>7x=42

hay x=6

b: =>5x=35

hay x=7

c: =>x-14=16

hay x=30

d: =>36-4x=4

=>4x=32