Question

Помогите решить через дискриминант.

Answer 1

$1)5x + 6 = {x}^{2} \ 5x + 6 - {x}^{2} = 0 \ - {x}^{2} + 5x + 6 = 0 times ( - 1)$
${x}^{2} - 5x - 6 = 0 \ d = 25 + 24 = 49 = {7}^{2}$
$x1 = frac{5 + 7}{2} = frac{12}{2} = 6 \ x2 = frac{5 - 7}{2} = - frac{2}{2} = - 1$
2)
$4x + 14(x - 3) = 3x(x - 3) \ 4x + 14x - 42 = {3x}^{2} - 9x \ 18x - 42 = 3 {x}^{2} - 9x \ 18x - 42 - 3 {x}^{2} + 9x = 0$
$- 3 {x}^{2} + 27x - 42 = 0 div ( - 3) \ {x}^{2} - 9x + 14 = 0 \ d = 81 - 56 = 25 = {5}^{2}$
$x1 = frac{9 + 5}{2} = frac{14}{2} = 7 \ x2 = frac{9 - 5}{2} = frac{4}{2} = 2$