Question

решите систему уравнений
x+3y=0         x^2+y^2-2xy=9

Answer 1

x+3y=0        
x^2+y^2-2xy=9
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(x-y)^2=9

x-y=3
x+3y=0
x+3y-x+y=0-3
4y=-3
y=-3/4
x=9/4
x-y=-3
x+3y=0
x+3y-x+y=0-(-3)
4y=3
y=3/4
x=-9/4