Question

решите систему уравнений
x+2y=7
xy=3

Answer 1

x=7-2y
y(7-2y)=3
7y-2y²=3
2y²-7y+3=0
D=49-24=25
y1=(7-5)/4=0,5⇒x1=7-2*0,5=6
y2=(7+5)/4=3⇒x2=7-2*3=1
(6;0,5);(1;3)