To factor the expression \(-36y^9 - 12y^7\), we need to find the greatest common factor (GCF) of the coefficients and the lowest power of \(y\).
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Finding the GCF of the coefficients:
- The coefficients are -36 and -12.
- The GCF of 36 and 12 is 12. Since we consider the negative sign, the GCF is -12.
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Finding the GCF of the \(y\) terms:
- The \(y\) terms are \(y^9\) and \(y^7\).
- The lowest power of \(y\) is \(y^7\).
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Combining the GCFs:
- Therefore, the overall GCF of the expression is \(-12y^7\).
Now we can factor the original expression:
\[ -36y^9 - 12y^7 = -12y^7(3y^2 + 1) \]
So, we have:
- GCF: \(-12y^7\)
- Factored form: \(-12y^7(3y^2 + 1)\)