Question

1) (a+1) (a -1) (a^2 +1)​

Answer 1

$\huge\rm\underline\red{SOLUTION:}$

$\large\rm{(a+1)(a-1)(a^2+1)}$

$\large\rm{=\:{a^2-1(a^2+1)}}$

$\large\rm\bold{\boxed{(a+b)(a-b)\;=\:a^2-b^2}}$

$\large\rm{=\:a^4-1}$

$\large\rm{\therefore{(a+1)(a-1)(a^2+1)\:=\:a^4-1}}$