Question

find the zeroes Of the quadratic polynomial 2x²-25

Answer 1

$2x {}^{2} - 25 = 0$

$2x {}^{2} - 5 {}^{2} = 0$

Now apply
$a {}^{2} - b {}^{2} = (a + b)(a - b)$


$= ( \sqrt{2} x + 5)( \sqrt{2} x - 5)$

$x = - 5 \div \sqrt{2} \: and \: 5 \div \sqrt{2}$


Thanks