himpunan penyelesaisn daei x-y =7 dan x+y =5 adalah

x-y = 7
x+y = 5

2x = 12
x = 12 : 2
x= 6

x-y = 7
6-y = 7
-y = 7-6
-y = 1
y = -1

hp { 6,-1 }

x - y =>> 7
x + y =>> 5
___________ +
2x =>> 12
x =>> 12/2
x =>> 6

x - y =>> 7
6 - y =>> 7
y =>> 6 - 7
y =>> - 1

semoga bermanfaat