Question

Plis bntu buat UN
14,15,16

Answer 1

14. terigu = x, beras = y

6x+10y=84000 |x1| 6x+10y=84000
10x+5y=70000 |x2| 20x+10y=140000 atas dikurangi bawah
-14x=-56000
x=4000

6x+10y=84000
6(4000)+10y=84000
10y=84000-24000
y=6000

8x+20y=8(4000)+20(6000)=32000+120000=152000 (B)

15. x+2y=4
      x-y=1 atas kurangi bawah
3y = 3
y=1

x+2y=4
x+2(1)=4
x=2

HP=(2,1)

16.