Answer:
[tex]a^{3y} + 1 = (a^{y}+1 )^{3} - 3a^y(a^{y}+1)\\\\[/tex]
Step-by-step explanation:
We are to factorize the expression [tex]a^{3y} + 1[/tex] completely. To do this, we will apply the expression below;
The expression can be rewritten as [tex]a^{3y} + 1^{3}[/tex]
To factorize the expression, we need to first factorize [tex](a^{y}+1 )^{3}[/tex] first
[tex](a^{y}+1 )^{3} =(a^{y}+1 )(a^{y}+1 )^{2}\\= (a^{y}+1 )((a^y)^{2} } + 2a^{y} +1)\\= (a^y)^{3} +2(a^y)^{2}+a^y+( a^y)^{2}+2a^y+1\\(a^{y}+1 )^{3} = ((a^y)^{3} + 1) +2(a^y)^{2}+a^y+( a^y)^{2}+2a^y\\(a^{y}+1 )^{3} = ((a^y)^{3} + 1) +3(a^y)^{2}+3a^y\\[/tex]
The we will make [tex]a^{3y} + 1^{3}[/tex] the subject of the formula as shown;
[tex](a^y)^{3} + 1 = (a^{y}+1 )^{3} - (3(a^y)^{2}+3a^y)\\(a^y)^{3} + 1^{3} = (a^{y}+1 )^{3} - (3(a^y)^{2}+3a^y)\\\\[/tex]
[tex](a^y)^{3} + 1 = (a^{y}+1 )^{3} - (3(a^y)^{2}+3a^y)\\\\[/tex]
[tex]a^{3y} + 1 = (a^{y}+1 )^{3} - (3(a^y)^{2}+3a^y)\\\\[/tex]
[tex]a^{3y} + 1 = (a^{y}+1 )^{3} - 3a^y(a^{y}+1)\\\\[/tex]
This last result gives the expansion of the expression