To determine which of the quadratic equations can be solved by factoring, we should first rearrange each equation into the standard form \( ax^2 + bx + c = 0 \) if necessary, and then check if they can be factored.
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\( x^2 + 9x = 8 \)
- Rearranging gives: \( x^2 + 9x - 8 = 0 \)
- This can be factored as \( (x + 8)(x + 1) = 0 \).
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\( x^2 = 2x + 8 \)
- Rearranging gives: \( x^2 - 2x - 8 = 0 \)
- This can be factored as \( (x - 4)(x + 2) = 0 \).
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\( x^2 = 4x - 10 \)
- Rearranging gives: \( x^2 - 4x + 10 = 0 \)
- This does not factor nicely over the real numbers.
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\( -12 = x^2 - x \)
- Rearranging gives: \( x^2 - x + 12 = 0 \)
- This does not factor nicely over the real numbers.
Thus, the equations that can be solved by factoring are:
- \( x^2 + 9x - 8 = 0 \)
- \( x^2 - 2x - 8 = 0 \)
In conclusion, the proper responses are:
- \( x^2 + 9x = 8 \)
- \( x^2 = 2x + 8 \)