Question

какие числа в сумме дают 7 , а в произведение 2 ?

Answer 1

$left { {{x+y=7} atop {xy=2}} right. left { {{y=7-x} atop {7x-x^2=2}} right. left { {{x+y=7} atop {x^2-7x+2=0}} right. left { {{y = sqrt{41}/2 + 7/2} atop {x = -sqrt(41)/2 + 7/2}} right.$