x - 2.3² : 3 = 12

=> x - 18 : 3 = 12

=> x - 6 = 12

=> x = 6 + 12 = 18        

mình muốn hỏi x-18:3=12

a) \(x\left(x-1\right)=0\)

\(\Rightarrow x=0\) hoặc \(x-1=0\)

+) \(x=0\)

+) \(x-1=0\Rightarrow x=1\)

Vậy \(x\in\left\{0;1\right\}\)

b) \(\left(x+2\right)\left(x-4\right)=0\)

\(\Rightarrow x+2=0\) hoặc \(x-4=0\)

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

+) \(x-4=0\Rightarrow x=4\)

Vậy \(x\in\left\{-2;4\right\}\)

c) \(x^3.x^2=2^8:2^3\)

\(\Rightarrow x^5=2^5\)

\(\Rightarrow x=2\)

Vậy \(x=2\)

d) \(3^{x-3}-3^2=2.3^2\)

\(\Rightarrow3^{x-3}=18+9\)

\(\Rightarrow3^{x-3}=27\)

\(\Rightarrow3^{x-3}=3^3\)

\(\Rightarrow x-3=3\)

\(\Rightarrow x=6\)

Vậy \(x=6\)

a) x(x-1)=0

=> x.x =0+1

=> x.x =1

=> x^2 =1

=> x^2 =1^2

=> x =1

8.9 - 3.(x + 2.9) + 6=0

72 - 3x +18.3 + 6 =0

(72+18.3 +6 ) -3x =0

(72+54+6) - 3x = 0

132 - 3x = 0

132 =3x 

x = 132 :3 =44

nhớ túch đúng cho mình nha =)))

Mình xin giải như sau:

a)15x-57=3^14:3^9

15.x-57=3^5

15.x-57=243

15.x=243+57

15.x=300

x=300:15

x=20

b)50-[70:(x-1)]=15

70:(x-1)=50-15

70:(x-1)=35

x-1=70:35

x-1=2

x=2+1

x=3

c) (5^2+2^3).x+4^2=7^2

(25+8).x+16=49

33.x=49-16

33.x=33

x=33:33

x=1

d) 2^x:2^5=1

2^x=1.2^5

2^x=2^5

Suy ra x=5

18-(x-2)^5=2.3^2

18-(x-2)^5=2.9

18-(x-2)^5=18

(x-2)^5=18-18

(x-2)^5=0

x=0+2

x=2