Răspuns: 121
Explicație pas cu pas:
[( x + y ) + ( y + 3 z ) ] × 2 + ( y + 3 z) = ( 29 + 21 ) × 2 + 21
( x + 2 y + 3 z ) × 2 + ( y + 3 z ) = 50 × 2 + 21
2 x + 4 y + 6 z + y + 3 z = 100 + 21
2 x + 5 y + 9 z = 121
x+y=29
y+3z=21
2x+5y+9z=?
aduni primele 2 relatii
x+y+y+3z=29+21
x+2y+3z=50
aduni x+y=29
2x+3y+3z=79
aduni y+3z=21
2x+4y+6z=100
2x+5y+9z=121
