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Daca 2x+3y=23 si 5y+8z = 97.calculati :
a) 2y + 8z– 2x ;
b) 4x +21y + 24 z
c) 33y + 72 z-8x
d) 10 x + 50 y + 56 z(dau coroana) ​

Răspuns :

Dianageorgiana794ask

Răspuns:

2x+3y=23

5y+8z = 97

a) 5y+8z-(2x+3y)=97-23

5y+8z-2x-3y=74

2y+8z-2x=74

b) 2x+3y=23 I·2=>4x+6y=46

5y+8z=97 I·3 =>15y+24z=291

4x+6y+15y+24z=46+291

4x+21y+24z=337

c) 2x+3y=23 I·4 =>8x+12y=92

5y+8z=97 I ·9 => 45y+72z=873

45y+72z -(8x+12y)=873-92

45y+72z-8x-12y=781

33y+72z-8x=781

d) 2x+3y=23 I·5 => 10x+15y=115

5y+8z=97 I·7 => 35y+56z=679

10x+15y+35y+56z=115+679

10x+50y+56z=794