Question

4x-y=-1
2x+y=13
cum se rezolva prin metoda substitutiei

Answer 1

4x -y = -1
2x + y = 13

y = 13- 2x
4x - 13 + 2x = -1

y = 13 - 2x
2x = 12

x = 6
y = 13 - 2*6
y = 13 -12
y =1

Answer 2

4x-y=-1
2x+y=13; y=13-2x

4x-(13-2x)=-1
4x-13+2x=-1
4x+2x=-1+13
6x=12
x=12:6
x=2

4*2-y=-1
8-y=-1
8+1=y
y=9