Question

x^2+20+91=0 по т. Виета

Answer 1

$x^2+20x+91=0\ left { {{x_1+x_2=-20} atop {x_1*x_2=91}} right. \\x_1=-7,x_2=-13$

Answer 2

х1+х2=-20
х1*х2=91

х1= -7

х2= -13