a)=> (a²-4b²)(a²+4b²)=
b)=>(x²-1)(x²+1)=>
=>
c)=>
a^{6}-64 " alt=" (a^{3}-8)(a^{3}+8)=>a^{6}-64 " align="absmiddle" class="latex-formula">
d)=>
c^{4} -5c^{2}+4 " alt=" c^{4}+c^{3}-2c^{2}-c^{3}-c^{2}+2c-2c^{2}-2c+4=>c^{4} -5c^{2}+4 " align="absmiddle" class="latex-formula">