Question

x.y = 8
x - y + 2 = 0

Dit : nilai x dan y ??

Answer 1

X.y = 8
   y = 8/x

   x - y + 2 = 0 ; subtitusi y = 8/x
x - 8/x + 2 = 0 ; kalikan x
x² - 8 + 2x = 0 
x² + 2x - 8 = 0
 (x+4)(x-2) = 0
              x = -4 atau x = 2

saat x = -4
y = 8/x
y = 8/(-4)
y = -2

saat x = 2
y = 8/x
y = 8/2
y = 4

HP (x,y) = (-4,-2) atau (2,4)