Question

1.rozwaz uklady rownan metoda podstawiania:

a) 3m+n=9

2m-5n=-11

b)4a-2=b

3a+7b=1,5

c)5x=4-2y

4x+y=3

d)6x-3y=9

x+5y=-9,5

tam sa klamry ale nie wstawilam ich...

2.rozwiaz podane uklady rownan metoda podstawiania:

a)x+2y=-2

2x-y=1

b)x=4y=-2

3x-8y=10

c)x-2y=3

-2x+y=0

d)2x+y=9

5x-4y=3

tutaj rowniez sa klamry wszedzie...

PROSZE WAS BARDZO O ROZWIAZANIE TYCH 2 ZADAN...

Answer 1

a) 3m+n=9

2m-5n=-11

{n=9-3m

{2m-5n=-11

 

{n=9-3m

{2m-5*(9-3m)=-11

 

{n=9-3m

{2m-45+15m=-11

 

{n=9-3m

{17m=34/:17   bo -11+45=34

 

{n=9-3n

{m=2

 

{n=9-3*2

{m=2

[n=3

[m=2

b)4a-2=b

3a+7b=1,5

[b=4a-2

[3a+7*(4a-2)=1,5

{b=4a-2

{3a+28a-14=1,5

[b=4a-2

[31a=15,5/:31

{b=4a-2

{a=0,5

[b=4*0,5-2

[a=0,5

{b=0

{a=0,5

c)5x=4-2y

4x+y=3

[5x+2y=4

[y=3-4x

{5x+2*(3-4x)=4

{y=3-4x

[5x+6-8x=4

[y=3-4x

{-3x=-2/:(-3)

{y=3-4x

[x=0,666(66666666666)

[y=3-4*0,666

{x=0,666

{y=-0,336

d)6x-3y=9

x+5y=-9,5

[6x-3y=9

[x=-9,5-5y

{6*(-9,5-5y)-3y=9

{x=-9,5-5y

[-57-30y-3y=9

[x=-9,5-5y

{-33y=66/:(-33)

{x=-9,5-5y

[y=-2

[x=-9,5-5*(-2)

{y=-2

{x=0,5

 

a)x+2y=-2

2x-y=1

{x=-2-2y

{2*(-2-2y)-y=1

[x=-2-2y

[-4-4y-y=1

{x=-2-2y

{-5y=5/:(-5)

[x=-2-2y

[y=-1

{x=-2-2*(-1)

{y=-1

[x=0

[y=-1

b)x=4y=-2

3x-8y=10

tu masz błąd dwa razy masz wstawione  =

c)x-2y=3

-2x+y=0

{x=3+2y

{-2*(3+2y)+y=0

[x=3+2y

[-6-4y+y=0

{x=3+2y

{-3y=6/:(-3)

[x=3+2y

[y=-2

{x=3+2*(-2)

{y=-2

[x=-1

[y=-2

d)2x+y=9

5x-4y=3

{y=9-2x

{5x-4*(9-2x)=3

[y=9-2x

[5x-36+8x=3

{y=9-2x

{13x=39/:13

[y=9-2x

[x=3

{y=9-2*3

{x=3

[y=3

[x=3