Question

Himpunan penyelesaian dari X-Y=7 Dan X+Y=5 adalah...

Answer 1

X + y = 5
x - y  = 77   -
   2y = -2
     y = -1

cari x
x + -1 = 5
x + -1 = 5
x = 5-(-1)
x = 6

HP = {x,y} = {-1,6}

Answer 2

Eliminasi y
-2y = 2
y = -1

subtitusi : x - y = 7
x - (-1) = 7
x + 1 = 7
x = 7 -1
x = 6