Question

Rozwiąż układy równań metodą 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

WAŻNE . !

Answer 1

a)

{n=9-3m

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

{n=9-3m

{2m-45+15m=-11

{n=9-3m

{17m=34

{n=9-3m

{m=2

{6+n=9

{m=2

{n=3

{m=2

b)

{4a-2 = b

{3a+7(4a-2)=1.5

{4a-2 = b

{3a+28a-14=1.5

{4a-2 = b

{31a=15.5

{4a-2 = b

{a=1/2

{2-2=b

{a=1/2

{b=0

c)

{y = 3-4x

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

{y = 3-4x

{5x=4-6+8x

{y = 3-4x

{-3x=-2

{y = 3-4x

{x=2/3

{y = 3-4x

{10/3 = 4-2y

{x=2/3

{-2/3=-2y

{x=2/3

{y=1/3

d)

{x= 5y = - 9,5

{6(-9.5) - 3y = 9

{x= 5y = - 9,5

{-57-3y=9

{x= 5y = - 9,5

{-60y=9

{x= 5y = - 9,5

{y=-0.15

{x=0.03

{y=-0.15