Question

решите системы уравнений: 1.

{-5x+5y= -2

{-5x+9y= 4

 

2.

{6x-y= 2

{-x+y= -1

 

3.

{3x+y= 3

{y-x^2= - 7

 

4.

{x+y= -5

{-y-x^2= 5

Answer 1

{-5x+5y= -2

{-5x+9y= 4

 

{-5x+5y= -2

{5x-9y= -4

-4y=-6y

y=1,5

x=-1,1

 

 

{6x-y= 2

{-x+y= -1

5x=1

x=0,2

y=-0,8

 

{3x+y= 3

{y-x^2= - 7

y=3-3x

3-3x-x^2=-7

x^2+3x-3-7=0

x^2+3x-10=0

D=7^2

x1=2

x2=-5

y1=-3

y2=18

 

 

{x+y= -5

{-y-x^2= 5

y=-5-x

-(-5-x)-x^2=5

5+x-x^2-5=0

-x^2+x=0

x^2-x=0

x(x-1)=0

x1=0 

x2=1

y1=-5

y2=-6