Question

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

Answer 1

 Here, we will use the identity​

\[\left( x + a \right)\left( x + b \right) = x^2 + \left( a + b \right)x + ab\].

\[\left( y^2 + 12 \right)\left( y^2 + 6 \right)\]

\[ = \left( y^2 \right)^2 + \left( 12 + 6 \right)\left( y^2 \right) + 12 \times 6\]

\[ = y^4 + 18 y^2 + 72\]