Question

Aflati x si y stiind ca
4x+3y =xy,. iar x este cu 3 mai mare decât y
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Answer 1

{4x+3y = xy

{x = 3+y

4(3+y)+3y = (3+y)y

12+4y+3y = 3y+y^2

12+4y-y^2 = 0

y^2-4y+12 = 0 /*(-1)

y^2-4y-12 = 0

y(y+2)-6(y+2) = 0

(y+2)(y-6) = 0

y₁ = -2

y₂ = 6

x₁=3-2

x₂=3+6

x₁ = 1

x₂ = 9

(x₁,y₁)=(1,-2)

(x₂,y₂)=(9,6)