Question

Find the following product: (y² + 12) (y² + 6)

Answer 1

 Here, we will use the identity​

$$(x+a)(x+b)=x^2+(a+b)x+ab$$.

$$(y^2+12)(y^2+6)$$

$$={\left(y^2\right)}^2+(12+6)\left(y^2\right)+12\times 6$$

$$=y^4+18y^2+72$$