Question

Dau 10 puncte
rezolvati sistemele vă roog e urgent am test
a)x-2y=-1
2x-y=7
b)4x-3y=20
5x+2y=2​
va roog ​​

Answer 1

Explicație pas cu pas:

a) x-2y=-1

2x-y=7

Metoda(1)

x-2y=-1 => x=-1+2y=-1+2×3=-1+6=5

2x-y=7. 2(-1+2y)-y=7=>-2+4y-y=7=>-2+3y=7=>3y=7+2=9/:(+3)=>y=3

b)4x-3y=20/×(+6) Metoda(2).

5x+2y=2/×(+9)

24x-18y=120(+)

45x+18y=18

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69x=138/÷(+69)

x=2

2×4-3y=20=>8-3y=20=>-3y=20-8=12/÷(-3)=>y=-4

Baftă !!!!!!!