Question

Реши уравнение: x2−11⋅x+28=0.

Answer 1

$x^{2}-11x+28=0\\\\D=(-11)^{2}-4*28=121-112=9=3^{2}\\\\x_{1}=\frac{11-3}{2}=4\\\\x_{2}=\frac{11+3}{2}=7\\\\Otvet:\boxed{4}$