Note: Although your statement sounds a little ambiguous, but I am assuming that you want to subtract [tex]a^4\:+\:40^2\:\cdot 62-\:264[/tex] from [tex]-3a^4\:+\:5a^{62}\:+264[/tex]. Anyways, even if you may have a slightly different expressions, but the procedure remains the same. So it would anyways help you understand the concept.
Answer:
[tex]-3a^4+5a^{62}+264-\left(a^4+40^2\cdot \:62-264\right)=5a^{62}-4a^4-98672[/tex]
Step-by-step explanation:
Given the expression
[tex]a^4\:+\:40^2\:\cdot 62-\:264[/tex]
which have to be subtracted from [tex]-3a^4\:+\:5a^{62}\:+264[/tex]
so
[tex]-3a^4+5a^{62}+264-\left(a^4+40^2\cdot \:62-264\right)[/tex]
[tex]=-3a^4+5a^{62}+264-\left(a^4+98936\right)[/tex] ∵ [tex]-\left(a^4+40^2\cdot \:62-264\right)=-\left(a^4+98936\right)[/tex]
[tex]=-3a^4+5a^{62}+264-a^4-98936[/tex]
[tex]\mathrm{Group\:like\:terms}[/tex]
[tex]=5a^{62}-3a^4-a^4+264-98936[/tex]
[tex]\mathrm{Add\:similar\:elements:}\:-3a^4-a^4=-4a^4[/tex]
[tex]=5a^{62}-4a^4+264-98936[/tex]
[tex]=5a^{62}-4a^4-98672[/tex]
Therefore,
[tex]-3a^4+5a^{62}+264-\left(a^4+40^2\cdot \:62-264\right)=5a^{62}-4a^4-98672[/tex]