We'll multiply the 1st equation by 1+x both
sides:
y*(1+x) = 5-x
We'll
remove the brackets:
y + x*y =
5-x
We'll move all terms to one
side:
y+x + x*y - 5 = 0
(3)
We'll factorize th second equation by
x*y:
x*y(x+y) = 6 (4)
We'll
substitute x+y = S and x*y = P
We'll re-write the equations
(3) and (4):
S+P-5=0 => S =
5-P
S*P=6
(5-P)*P=6
We'll
remove the brackets:
-P^2 + 5P - 6 =
0
P^2 - 5P + 6 = 0
P1 = 1
=> S1 = 5-1=4
P2 = 5 => S2 = 5-5 =
0
x + y = S1 <=> x+y =
4
x*y= P1 <=> x*y =
1
x^2 - Sx + P = 0
x^2 - 4x +
1 = 0
x = [4+sqrt(16-4)]/2
x =
[4+sqrt(12)]/2
x =
(4+2sqrt3)/2
x = 2+sqrt3 ; y =
2-sqrt3
x = 2-sqrt3 ; y =
2+sqrt3
x + y = S2 <=> x+y =
0
x*y= P2 <=> x*y =
5
x^2 + 5 = 0
impossible!
There are no real values of x to satisfy the
equation.
The lines are intercepting in the
points (2+sqrt3 ; 2-sqrt3) and (2-sqrt3 ;
2+sqrt3).
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