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Quadratic Equations — Maths STD 11 Science — Question

CBSE BoardEnglish MediumSTD 11 ScienceMathsQuadratic Equations2 Marks
Question
Show the following quadratic equation by factorization method:
$x^2 + 10ix - 21 = 0$
✓

Answer

$x^2 + 10ix - 21 = 0$
$\Rightarrow x^2 + 10ix + 21i^2 = 0$
$\Rightarrow x^2 + 7ix + 3ix + 21i^2 = 0$
$\Rightarrow (x + 3i) (x + 7i) = 0$
$\therefore\text{x}=-3\text{i},-7\text{i}$

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