Answer
$(7x^{4}+x^{2}+3)(x-1)$
Work Step by Step
Group in pairs...
... $= [7x^{4}\cdot x+7x^{4}\cdot(-1)]+ [x^{2}\cdot x+x^{2}\cdot(-1)]+[3\cdot x+3\cdot(-1)]$
... use the distributive property on each pair,
$=7x^{4}(x-1)+x^{2}(x-1)+3(x-1)$
... now, $(x-1)$ is a common factor. Use the distributive property.
= $(7x^{4}+x^{2}+3)(x-1)$
