Question

решите систему уравнений x^2-y=16,x+y=4

Answer 1

$left { {{x^2-y=16} atop {x+y=4}} right. left { {{x^2+x-4=16} atop {y=4-x}} right. \x^2+x-4=16\x^2+x-20=0\D=81\x_1=4\x_2=-5\y_1=0\y_2=9$