x = 8

a) x = 8.

b) x = -5.

c) x = 5.

d) x = -3.

x = 64 : 8 = 8

x = 64 : 8 = 8

a)  x = 64 : 8 = 8

b)  x = 60 : − 15 = − 4

c) 

12 x = 30 − 6 12 x = 24       x = 24 : 12       x = 2

d)

− 11 . x = 130 − 9 − 11 . x = 121                x = 121 : − 11                x = − 11

a)  x = 64 : 8 = 8

b)  x = 60 : − 15 = − 4

c) 

12 x = 30 − 6 12 x = 24       x = 24 : 12       x = 2

d)

− 11 . x = 130 − 9 − 11 . x = 121                x = 121 : − 11                x = − 11

a) \(2^x=8\)

⇔ \(2^x=2^3\)

⇒ \(x=3\)

b) \(3^x=27\)

⇔ \(3^x=3^3\)

⇒ \(x=3\)

c) \(\left(-\dfrac{1}{2}\right)x=\left(-\dfrac{1}{2}\right)^4\)

⇔ \(x=\left(-\dfrac{1}{2}\right)^4\div\left(-\dfrac{1}{2}\right)\)

⇔ \(x=\left(-\dfrac{1}{2}\right)^3\)

d) \(x\div\left(-\dfrac{3}{4}\right)=\left(-\dfrac{3}{4}\right)^2\)

⇔ \(x=\left(-\dfrac{3}{4}\right)^2\cdot\left(-\dfrac{3}{4}\right)\)

⇔ \(x=\left(-\dfrac{3}{4}\right)^3=-\dfrac{27}{64}\)

d) \(\left(x+1\right)^3=-125\)

⇔ \(\left(x+1\right)^3=\left(-5\right)^3\)

⇔ \(x+1=-5\)

⇔ \(x=-5-1=-6\)

2:

a: (x-1,2)^2=4

=>x-1,2=2 hoặc x-1,2=-2

=>x=3,2(loại) hoặc x=-0,8(loại)

b: (x-1,5)^2=9

=>x-1,5=3 hoặc x-1,5=-3

=>x=-1,5(loại) hoặc x=4,5(loại)

c: (x-2)^3=64

=>(x-2)^3=4^3

=>x-2=4

=>x=6(nhận)

=>10x=-100

hay x=-10

⇒3x+7x=-64-36

⇒10x=-100

⇒x=-10