Question
Simplify:$(2x - 4y + 7)(2x + 4y + 7)$
✓
Answer
$(2x - 4y + 7)(2x + 4y + 7)$
$= (2x + 7 - 4y)(2x + 7 + 4y)$
$= (2x + 7)^2 - (4y)^2$
$= 4x^2+ 2(2x)(7) + 7^2 - 16y^2$
$= 4x^2 - 16y^2 + 28x + 49.$
$= (2x + 7 - 4y)(2x + 7 + 4y)$
$= (2x + 7)^2 - (4y)^2$
$= 4x^2+ 2(2x)(7) + 7^2 - 16y^2$
$= 4x^2 - 16y^2 + 28x + 49.$
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