Question

rezolvati prin metoda substitutiei !!! va rooooogggg dau test !!! ​

Answer 1

Răspuns:

b) 3(x-1)+y= -5 => 3x-3+y= -5 => y= -5-3x+3 => y= -3x-2

2x+2(y+1)=6 => 2x+2(-3x-2+1)=6

2x-6x-4+2=6

-4x-2=6

-4x=6+2

-4x=8

4x= -8

x= -2

y= -3*(-2)-2

y=6-2

y=4

e)2(x+4)= -3(y-5) => 2(2y-15+4)= -3y+15

x=2(y+1)-16 => x=2y+1-16 => x=2y-15 (cu care revii mai sus)

2(2y-11)= -3y+15

4y-22= -3y+15

4y+3y=15+22

7y=37

y=37/7 (fracție)

x=2*37/7+15 (amplifică 15 cu 7)

x=74/7+105/7

x=179/7