Question

Tìm số nguyên x,biết:

a,(2x-1)² = 9

b,2x(x-3) = 0

giúp mik với!!

Answer 1

a)

(2x-1)²=9

<=> 2x-1=\(\sqrt{9}\)

<=> 2x-1=3

<=> 2x=4

<=> x=2

b)

2x(x-3)=0

\(\Leftrightarrow\orbr{\begin{cases}x=0\\x-3=0\end{cases}\Leftrightarrow}\orbr{\begin{cases}x=0\\x=3\end{cases}}\)

Vậy x=0 hoặc x=3

Answer 2

Tìm số nguyên x,biết:

a,(2x-1)² = 9

\(\Rightarrow\left(2x-1\right)^2=3^2\)

\(\Rightarrow2x-1=3\)

\(\Rightarrow2x=4\Rightarrow x=2\)

b,2x(x-3) = 0

\(\Rightarrow\orbr{\begin{cases}2x=0\\x-3=0\end{cases}}\)\(\Rightarrow\orbr{\begin{cases}x=0\\x=3\end{cases}}\)

giúp mik với!!

Answer 3

b.x=3

a. x=2

Answer 4

a) (2x-1)^2=3^2

Suy ra 2x-1=3

            2x   =3+1

           2x    =4

             x    =4:2

             x=2

  Vậy x=2

b)x-3=0:2

    x-3=0

    x   =0+3

    x   =3

Vậy x=3

Answer 5

\(\text{a) }\left(2x-1\right)^2=9\)
\(\Rightarrow2x-1=\pm3\)
\(\cdot\text{TH1}:2x-1=3\text{ }\Leftrightarrow\text{ }2x=4\text{ }\Leftrightarrow\text{ }x=2\)
\(\cdot\text{TH2:}2x-1=-3\text{ }\Leftrightarrow\text{ }2x=-2\text{ }\Leftrightarrow\text{ }x=-1\)
\(\text{Vậy }x=\left\{-1;2\right\}\)

\(\text{b) }2x\left(x-3\right)=0\)
\(\Rightarrow2x=0\text{ hoặc }x-3=0\)
\(\Rightarrow x=0\text{ hoặc }x=3\)

\(\text{Vậy }x=\left\{0;3\right\}\)

Answer 6

a)\(\left(2x-1\right)^2=9\)

\(\Rightarrow\left(2x-1\right)^2=3^2\)

\(\Rightarrow2x-1=3\)

\(\Rightarrow2x=3-1\)

\(\Rightarrow2x=2\)

\(\Rightarrow x=2:2\)

\(\Rightarrow x=1\)

vậy x=1

Answer 7

a, (2x - 1)² = 9

\(\Rightarrow\orbr{\begin{cases}\left(2x-1\right)^2=3^2\\\left(2x-1\right)^2=\left(-3\right)^2\end{cases}\Rightarrow\orbr{\begin{cases}2x-1=3\\2x-1=-3\end{cases}}}\Rightarrow\orbr{\begin{cases}2x=3+1=4\\2x=-3+1=2\end{cases}}\Rightarrow\orbr{\begin{cases}x=4\div2=2\\x=2\div2=1\end{cases}}\)

\(\Rightarrow x\in\left\{2;1\right\}\)

b, 2x(x - 3) = 0

\(\Rightarrow\orbr{\begin{cases}2x=0\\x-3=0\end{cases}}\Rightarrow\orbr{\begin{cases}x=0\div2=0\\x=0+3=3\end{cases}}\)

\(\Rightarrow x\in\left\{0;3\right\}\)