Answer:
The factor by grouping 7c^4 - 4c^3 + 28c^2 - 16c is [tex]\left(c^{2}+4\right)(7 c-4) c[/tex]
Solution:
[tex]\text { Given, expression is } 7 \mathrm{c}^{4}-4 \mathrm{c}^{3}+28 \mathrm{c}^{2}-16 \mathrm{c}[/tex]
We have to factor the given expression by grouping.
[tex]\text { Now, } 7 c^{4}-4 c^{3}+28 c^{2}-16 c[/tex]
[tex]\rightarrow 7 c^{4}+28 c^{2}-4 c^{3}-16 c[/tex]
By grouping the terms we get,
[tex]\rightarrow\left(7 c^{4}+28 c^{2}\right)-\left(4 c^{3}+16 c\right)[/tex]
By taking the common terms out from groups,
[tex]\rightarrow 7 c^{2}\left(c^{2}+4\right)-4 c\left(c^{2}+4\right)[/tex]
[tex]\text { Taking } \mathrm{c}^{2}+4 \text { as common }[/tex]
[tex]\rightarrow\left(c^{2}+4\right)\left(7 c^{2}-4 c\right)[/tex]
[tex]\Rightarrow\left(c^{2}+4\right)(7 c-4) c[/tex]
Hence, the factorization of given expression is [tex]\left(c^{2}+4\right)(7 c-4) c[/tex]