[tex]\\ \sf\longmapsto 2+y=-2x---(1)[/tex]
[tex]\\ \sf\longmapsto -2x^2+8xy+42=y\dots(2)[/tex]
From equation (1)
[tex]\\ \sf\longmapsto y=-2x-2\dots(3)[/tex]
Put in eq(2)
[tex]\\ \sf\longmapsto -2x^2+8x(-2x-2)+42=-2x-2[/tex]
[tex]\\ \sf\longmapsto -2x^2-16x^2-16x+42=-2x-2[/tex]
[tex]\\ \sf\longmapsto -18x^2-16x+2x+42+2=0[/tex]
[tex]\\ \sf\longmapsto -18x^2-14x+44=0[/tex]
On solving
[tex]\\ \sf\longmapsto x=\dfrac{11}{9}\:or\;-2[/tex]
Take it whole.
Put in eq(3)
[tex]\\ \sf\longmapsto y=-2(-2)-2=4-2=2[/tex]
Hence
