10,5=2*(x+y),5,30=x*y решите систему уравнения, )

{2(x+y)=10,5|:2
{x×y=5,3
{(x+y)=5,25
{x×y=5,3
x=5,25-y
y×(5,25-y)=5,3
5,25y- y^2=5,3
y^2-5,25y+5,3=0
D=(-5,25)^2-4×1×5,3=27,5625-21,2=6,3625
y1=(-(-5,25)-V6,3625)/2×1=2,73/2=1,36
y2=(-(-5,25)+V6,3625)/2×1=7,78/2=3,89
x1=5,25-y1=5,25-1,36
x1=3,89
x2=5,25-y2=5,25-3,89
x2=1,36

(3,89;1,36) и (1,36;3,89)