Question

Write the following square of binomial as trinomial: (x + 2)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.

\[\left( x + 2 \right)^2 \]

\[ = x^2 + 2 \times x \times 2 + b^2 \]

\[ = x^2 + 4x + b^2\]