Question

Очень срочно!!
f(x)=x²-2x-3

f(x)=5

x=?

Answer 1

Ответ:

${x}^{2} - 2x - 3 = 5 \\ {x}^{2} - 2x - 3 - 5 = 0 \\ {x}^{2} - 2x - 8 = 0 \\ x_{1} \times x_{2} = - 8 \\ x_{1} + x_{2} = 2 \\ x_{1} = - 2\\ x_{2} = 4$