Question

find the discriminant of 2x square + 10x+21=0

Answer 1

discriminant of
$2 {x}^{2} + 10x + 21 = 0 \: is \\ {10}^{2} - 4 \times 2 \times 21 \\ = - 68 \\ i.e. \: for \: a {x}^{2} + bx + c = 0 \\ {b}^{2} - 4ac$
hope it helps

Answer 2

$2 {x}^{2} + 10x + 21 = 0 \\ \\here \\ a = 2 \\ b = 10 \\ c = 21 \\ \\ discriminant = {b}^{2} - 4ac \\ \\ = {10}^{2} - 4 \times 2 \times 21 \\ \\ = 100 - 168 \\ \\ = - 68$