Question

13.Rezolvayi prin metoda substitutiei urmatoarele sisteme de ecuații:

b { -x+y=4
{5c+2y=8


c{-3x+4y=-6
{2x+y=4


d{2x-3y=-3
{3x+y=12




VA ROGG!!!!!
URGENT , DAU COROANA!!

Answer 1

Răspuns:

b) -x=4-y

5x+2y=8

x=-4+y

5x+2y=8

5(-4+y)+2y=8

-20+5y+2y=8

7y=28

y=4

-x+4=4

-x=0

x=0

c)-3x+4y=-6

y=4-2x

-3x+4(4-2x)=-6

-3x+16-8x=-6

-11x=-6-16=-22

11x=22

x=2

4+y=4

y=0

d) 2x-3y=-3

y=12-3x

2x-3(12-3x)=-3

2x-36+9x=-3

11x=-3+36=33

11x=33

x=3

9+y=12

y=3