Tolong bantu jawab yaa.... Jgn lupa pakai Cara... Jawabnya pake begini : Diket: Dit: Penyelesaian: Yg udah jawab thanks....

4. 9x + ky = 1 ( 1, 2 )
9(1) + k(2) = 1
9 + 2k = 1
2k = 1 - 9
2k = -8
k = -8/2
= -4
5. Buku tulis = b
Pulpen = p
5b + 2p = 19.000
3b + p = 11.000

6b + 2p = 22.000
5b + 2p = 19.000
-------------------------- -
b = 3.000
2b = 2 x 3.000
= 6.000