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√4x-3=2x-3 can you compute it?

User Deidre
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1 Answer

12 votes
12 votes

Given the equation:


\sqrt[]{4x-3}=2x-3

Let's solve the equation for x.

Square both sides:


\begin{gathered} (\sqrt[]{4x-3})^2=(2x-3)^2 \\ \\ 4x-3=(2x-3)(2x-3) \end{gathered}

Solving further:

Expand using the FOIL method.


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

Apply distributigve property:


\begin{gathered} 4x-3=2x(2x)+2x(-3)-3(2x)-3(-3) \\ \\ 4x-3=4x^2-6x-6x+9 \\ \\ 4x-3=4x^2-12x+9 \end{gathered}

Move all terms to the left and equate to zero:


\begin{gathered} 4x^2-12x+9-4x+3=0 \\ \\ 4x^2-12x-4x+9+3=0 \\ \\ 4x^2-16x+12=0 \end{gathered}

Factor the left side of the equation:


\begin{gathered} 4(x^2-4x+3)=0 \\ \\ 4(x-3)(x-1)=0 \end{gathered}

Equate each factor to zero and solve for x.

x - 3 = 0

Add 3 to both sides:

x - 3 + 3 = 0 + 3

x = 3

x - 1 = 0

Add 1 to both sides:

x - 1 + 1 = 0 + 1

x = 1

Hence, we have:

x = 3 and 1

Now, let's exclude the solution that do not make the equation true.

Input 3 for x in the equation:


\begin{gathered} \sqrt[]{4(3)-3}=2(3)-3 \\ \\ \sqrt[]{12-3}=6-3 \\ \\ \sqrt[]{9}=3 \\ \\ 3=3 \end{gathered}

The value of 3 makes the equation true.

Input 1 for x in the equation and evaluate:


\begin{gathered} \sqrt[]{4(1)-3}=2(1)-3 \\ \\ \sqrt[]{1}=-1 \\ \\ 1\\e-1 \end{gathered}

The value of 1 do NOT make the equation true.

Therefore, the correct solution for x in the equation is 3.

ANSWER:

x = 3

User Vito Gentile
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