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Question 6 of 10

Complete the square for [tex]$5x^2 - 30x = 5$[/tex].

A. [tex]$(x-3)^2 = 10$[/tex]
B. [tex][tex]$(x+3)^2 = 10$[/tex][/tex]
C. [tex]$(5x-3)^2 = 8$[/tex]
D. [tex]$(5x-3)^2 = 14$[/tex]



Answer :

Let's solve the equation [tex]\( 5x^2 - 30x = 5 \)[/tex] by completing the square.

1. Rewrite the equation in standard form:

[tex]\( 5x^2 - 30x - 5 = 0 \)[/tex]

2. Divide the entire equation by 5, the coefficient of [tex]\( x^2 \)[/tex]:

[tex]\( x^2 - 6x - 1 = 0 \)[/tex]

3. Move the constant term to the right side of the equation:

[tex]\( x^2 - 6x = 1 \)[/tex]

4. Complete the square:
- Take half of the coefficient of [tex]\( x \)[/tex], which is [tex]\(-6\)[/tex], divide by 2, and square it:
[tex]\( \left( \frac{-6}{2} \right)^2 = 9 \)[/tex]
- Add and subtract this square inside the equation:

[tex]\( x^2 - 6x + 9 - 9 = 1 \)[/tex]

5. Rewrite the left side as a perfect square:

[tex]\( (x - 3)^2 - 9 = 1 \)[/tex]

6. Move the [tex]\(-9\)[/tex] to the right side:

[tex]\( (x - 3)^2 = 1 + 9 \)[/tex]

7. Simplify the right side:

[tex]\( (x - 3)^2 = 10 \)[/tex]

Thus, the correct answer is:

A. [tex]\((x - 3)^2 = 10\)[/tex]