Question

Rezolvati SISTEMUL:3(x+y)+4(1-y)=x+5

4(x-y)+5+8y=5(x+y)

va rog rapid

Answer 1

Răspuns:

Explicație pas cu pas:

{ 3(x+y)+4(1-y)=x+5

{ 4(x-y)+5+8y=5(x+y)  <=>

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

4x-4y+5+8y = 5x+5y =>

3x-x-y = 5-4

4x-5x+4y-5y = -5

2x-y = 1

-x-y = -5   I·(-1) =>

2x-y = 1

x+y = 5

______

3x = 6  => x = 6:3 => x = 2

y = 5-x => y = 5-2 => y = 3