Question

Write the following square of binomial as trinomial:  (x² − ay)²

Answer 1

 We will use the identities

\[\left( a + b \right)^2 = a^2 + 2ab + b^2 \text { and } \left( a - b \right)^2 = a^2 - 2ab + b^2\] to convert the squares of binomials as trinomials.

\[ \left( x^2 - ay \right)^2 \]

\[ = \left( x^2 \right)^2 - 2 x^2 \left( ay \right) + \left( ay \right)^2 \]

\[ = x^4 - 2 x^2 ay + a^2 y^2\]