Question

rozwiąż układy równań metodą podstawiania.

a ) x = -y

2x-3y = 10

b) x-2=2y

x+ 2y=-6

c) y=⅔x

4x-3y= 1

d) -2x-3y=-2

x-y=6

Answer 1

a ) x = -y

2x-3y = 10

x = -y

2*(-y)-3y=10

x = -y

-2y-3y=10

x = -y

-5y=10/:(-5)

x = -y

y=-2

x=-(-2)

y=-2

x=2

b) x-2=2y

x+ 2y=-6

x=2y+2

2y+2+2y=-6

x=2y+2

4y=4/:4

x=2y+2

y=1

x=2*1+2

y=1

x=4

c) y=⅔x

4x-3y= 1

y=⅔x

4x-3*⅔x=1

y=⅔x

⅓x=1/*3

y=⅔x

x=3

y=⅔*3

x=3

y=2

d) -2x-3y=-2

x-y=6

-2x-3y=-2

x=6+y

-2(6+y)-3y=-2

x=6+y

-12-2y-3y=-2

x=6+y

-5y=10/:(-5)

x=6+y

y=-2

x=6-2

y=-2

x=4

 

liczę na naj ;d