Question

Answer 1

`1)(x-3)^2=49`

`<=>[(x-3=7),(x-3=-7):}`

`<=>[(x=10),(x=-4):}`

Vậy `S={-4;10}`

`2)4x^2-4x+1=16`

`<=>(2x-1)^2=16`

`<=>[(2x-1=4),(2x-1=-4):}`

`<=>[(2x=5),(2x=-3):}`

`<=>[(x=5/2),(x=-3/2):}`

Vậy `S={-3/2;5/2}`

`3)(3x-1)^3=8`

`<=>3x-1=2`

`<=>3x=1+2=3`

`<=>x=1`

Vậy `S={1}`

`4)(x-21)^3=-27`

`<=>x-21=-3`

`<=>x=-3+21`

`<=>x=18`

Vậy `S={18}`

Answer 2

1/ \(\Leftrightarrow x-3=7\)

\(\Leftrightarrow x=10\)

Vậy ..

2/ \(\Rightarrow\left(2x-1\right)^2=4^2\)

\(\Leftrightarrow2x-1=4\)

\(\Leftrightarrow x=\dfrac{5}{2}\)

Vậy ..

3/ \(\Rightarrow3x-1=2\)

\(\Leftrightarrow x=1\)

Vậy..

4/ \(\Leftrightarrow x-21=-3\)

\(\Leftrightarrow x=18\)

Vậy ..