Question 1100968
{{{x^2}}} is a factor common to both terms, so
{{{x^4 + 49x^2=x^2(x^2 + 49)}}}
The factor {{{x^2+49}}} cannot be further factored with real numbers,
because {{{x^2+49}}} is not zero for any reaal number value of {{{x}}} .
If you were allowed to use imaginary (complex) numbers,
you could further factor {{{x^2+49=(x-7i)(x+7i)}}}