Question

Himpunan penyelesaian sistem persamaan y=x kuadrat dan x-y-2=0

Answer 1

Y = x²
x-y = 2

subtitusi y = x²
           x-y = 2
          x-x² = 2
          x²-x = -2
x²-x+(1/4) = -2+(1/4)
(x-(1/2))² = -7/4
    x-(1/2) = √(-7/4) atau x-(1/2) = -√(-7/4)
    x-(1/2) = (1/2).i.√7 atau x-(1/2) = -(1/2).i.√7
            x = (1/2).(1+i√7) atau x = (1/2).(1-i√7)

saat x= (1/2).(1+i√7)  
       y = (i/2).(√7+3i)

saat x= (1/2).(1-i√7)
       y = -(i/2).(√7-3i)

Answer 2

Y=x²
x-y-2=0

y-x²=0
-y+x=2

di tambah, jadi
x=2

kalau di masukin ke persamaan nya lagi, jadi
-y+x=2
-y+2=2
-y=2-2
y=0