it makes me sad that you can't figure out the first one.
any of these will do
\(c_1 a^{m_1}b^{n_1} \cdot c_2 a^{m_2}b^{n_2} \\ \text{where } \dots \\ c_1 \cdot c_2 = -84 \\ m_1 + m_2 = 6 \\ n_1 + n_2 = 10 \\ \text{use your rainbow panda powers to choose two monomial that satisfy these 3 requirements!}\)
for the second one we know (should know) that the volume of a cube is \(s^3 \text{ where s is the length of a side.}\)
our side length is doubled giving us \(s=4x^5\)
Thus the new volume is \(\left(4x^5\right)^3 = 4^3 \cdot x^{5 \cdot 3} = 64 x^8\)
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