Question

sisteme de ecuatii - metoda reducerii
1) 2x + y = 10
x - 2y = -5

2) 3x - 5y = 6
-4x +2y = 6

urgent va rog! am nevoie pas cu pas

Answer 1

1) 2x+y=10

x-2y=-5

scazi ecuatiile

2x+y-x+2y=10+5

x+3y=15 (scazi a 2-a ecuatie)

x+3y-x+2y=15+5

3y+2y=20

5y=20

y=4

2x+4=10

2x=6

x=3

2) 3x-5y=6

-4x+2y=6

scazi ecuatiile

3x-5y+4x-2y=6-6

7x-7y=0

7(x-y)=0

==>x-y=0

in prima ecuatie:

3(x-y)-2y=6

0-2y=6

-2y=6

2y=-6

y=-3

x-y=0

x+3=0

x=-3

Answer 2

Răspuns:

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