Question 4: Factor the following polynomials: \(x ^2 + 4 y ^2 + 4 x y − 16\)
\( {{\mkern 1mu} {\mkern 1mu} {x^2} + 4{y^2} + 4xy – 16 = \left( {{x^2} + 4xy + 4{y^2}} \) right) – 16 = {{(x + 2y)}^2} – {4^2} = (x + 2y + 4)(x + 2y – 4)}\)
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