Question

Решить уравнение х²+8х+15=0

Answer 1

${x}^{2} + 8x + 15 = 0$
D=
${8}^{2} - 4 times 15 times 1 = 64 - 60 = 4 = {2}^{2}$
$x = frac{ - 8 + - 2}{2} = - 3. - 5$
X= - 3 и - 5