Question

Отметьте уравнение, дискриминант которого равен 49.

1) 2х^2-3x-5=0

2)2х^2-3x+5=0

3)3x^2-3x-7=0

4) 5x^2+3x+2=0

Answer 1

Ответ:

1)

Объяснение:

1)

$2 {x}^{2} - 3x - 5 = 0 \ D = {( - 3)}^{2} - 4 times 2 times ( - 5) = 9 + 40 = 49$

2)

$2 {x}^{2} - 3x + 5 = 0 \ D = {( - 3)}^{2} - 4 times 2 times 5 = 9 - 40 = - 31$

3)

$3 {x}^{2} - 3x - 7 = 0 \ D = {( - 3)}^{2} - 4 times 3 times ( - 7) = 9 + 84 = 93$

4)

$5 {x}^{2} + 3x + 2 = 0 \ D = {3}^{2} - 4 times 5 times 2 = 9 + 20 = 29$