#matematika wjib kls 10

Misal Jeruk = x , Apel = y , Mangga = z

Maka
25x + 15y + 20z = 555000 ... (i)
x = 3000 + z , z = x - 3000 ... (ii)
y = 5000 + x ... (iii)

Sederhanakan persamaan (i)
25x + 15y + 20z = 555000
5(5x + 3y + 4z) = 555000
5x + 3y + 4z = 111000 ... (iv)

Subtitusi persamaan (iii) ke (iv)
5x + 3(5000 + x) + 4z = 111000
5x + 3x + 15000 + 4z = 111000
8x + 4z = 96000 ... (v)

Eliminasi persamaan (v) dan (ii)
x - z = 3000 |x 4|
8x + 4z = 96000
_____________ (+)
12x = 108000
x = 9000

Subtitusi nilai x ke persamaan (ii)
z = 9000 - 3000
z = 6000

Subtitusi nilai x ke persamaan (iii)
y = 5000 + 9000
y = 14000

Jadi , jeruk / kg = Rp9000 ; Apel / kg = Rp14000 ; Mangga / kg = Rp6000

Harga yang harus dibayar Bu Zakinah = Rp9000 + Rp14000 + Rp6000 = Rp29000

jeruk= x
apel=y
mangga=z

x=z+3000
y=x+5000

25x+15y+20z=Rp555.000
25(z+3000)+15(x+5000)+20z=Rp555.000
25z+75000+15((z+3000)+5000)+20z=555000

25z+75000+15z+120000+20z=555000
25z+15z+20z=555000-75000-120.000
60z=360.000
z=6000


x=6000+3000=9000
y=9000+5000=14000

x+y+z?
9000+14000+6000=29.000 A