3 kursi 5 meja dan 2 bangku=330.000 7 kursi 2meja 1bangku=250.000 12kursi 6meja 7bangku=610.000 harga tiap kursi,meja,dan bangku?

misal:
x= kursi
y= meja
z= bangku

3x+ 5 y + 2z = 330k
7x + 2 y+ 1 z = 250k
12x + 6 y + 7z = 610k


3x =330k- 5y -2z
x= 110k -5/3y -2/3z

12x+6y + 7z = 610k
4(3x) + 6y + 7z = 610k
4(330k-5y-2z) + 6y +7z =610k
1320k -20y -8z +6y+7z= 610k
1320k-610k = 14y + 1z
710k -14y =z

7(110k -5/3y-2/3(710k-14y))+2y+(710k-14y)=250k

770k -35/3y - 3.313,333 +196/3 y+2y + 710k -14y =250k

2.083,333= 2y +161/3y -14y
2.083,333= 41.667y
y= 49.999
y=50.000

710k - 14y = z
710k - 14 (50k) =z
z= 10.000

7 x+2y +z = 250k
7x + 100k + 10k =250k
7x = 250k- 110k
7x = 140k
x= 20.000