Question

Gwen was asked to solve 3x2−20=7 by factoring using the difference of squares pattern. What is/are the correct solution(s)?(1 point)
Responses

x=−3, x=3
x equals negative 3 , x equals 3

x=3
x equals 3

x=9, x=−9
x equals 9 , x equals negative 9

x=−3

Answers

GPT-4o mini
To solve the equation \(3x^2 - 20 = 7\) by factoring, we first need to rearrange the equation:

1. Move all terms to one side:
\[
3x^2 - 20 - 7 = 0 \quad \Rightarrow \quad 3x^2 - 27 = 0
\]

2. Factor out the common factor of 3:
\[
3(x^2 - 9) = 0
\]

3. Next, we can use the difference of squares pattern, which states that \(a^2 - b^2 = (a - b)(a + b)\). In this case, \(x^2 - 9\) can be factored as follows:
\[
x^2 - 9 = (x - 3)(x + 3)
\]

4. Putting it all together, we have:
\[
3(x - 3)(x + 3) = 0
\]

5. Setting each factor equal to zero gives us the solutions:
\[
x - 3 = 0 \quad \Rightarrow \quad x = 3
\]
\[
x + 3 = 0 \quad \Rightarrow \quad x = -3
\]

Thus, the correct solutions to the equation are:

**x = -3, x = 3**.

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