Jika p dan q = penyelesaian dari p persamaan 3p + 4q =8 dan 2p -5q =13 maka 2p-q =?

Materi SPLDV

3p + 4q = 8 ........ x 2
2p - 5q = 13 ........ x 3

pake metode eliminasi
6p + 8q = 16
6p - 15q = 39
——————— -
23q = - 23
q = 23/-23 = -1

substitusi nilai q
3p + 4q = 8
=> 3p + (4 x -1) = 8
=> 3p + (-4) = 8
=> 3p = 8 + 4
=> 3p = 12
=> p = 4

2p - q = (2 x 4) - (-1)
=> 8 + 1
=> 9

semoga membantu

3p + 4q = 8    dikalikan 2 -----> 6p + 8q   = 16
2p - 5q = 13   dikalikan 3 -----> 6p - 15q = 39
                                                -------------------- -
                                                         23q = - 23
                                                             q = - 1
3p + 4q = 8
3p + 4(-1) = 8
       3p = 8 + 4
         p = 12/3

maka 2p - q = 2(12/3) - (-1)
                    = 24/3 + 3/3
                    = 27/3
                    = 9