jika x dan y sistem persamaan 5x-3y=20 dan 3x-5y=-4 maka nilai 6x-4y =

5x - 3y = 20 ....... persamaan 1
3x - 5y = -4........ persamaan 2

eliminasi nilai x (5 kali persamaan 1 dikurang 3 kali persamaan 2)
15x - 9y = 60
15x - 25y = -20 _
         16y = 80
             y = 5

cari nilai x :
5x - 3y = 20
5x - 3. 5 = 20
5x - 15 = 20
5x = 20 + 15
5x = 35
x = 7

didapat x = 7, y = 5

6x - 4y = 6. 7 - 4. 5 = 42 - 20 = 22

●5x-3y=20 |x3| 》15x-9y=60
3x-5y=-4 |x5| 》15x-25y=-20 dieliminasi
-9y+25y=60+20 》16y=80
y=80÷16
y=5
●subtitusi
5x-3.5=20
5x-15=20
5x=20+15
5x=35
x=35÷5
x=7
●hasil akhir
6x-4y
6x7-4x5
42-20
22