Question

Proszę o pomoc !!

Rozwiąż układy równań .

a) {y-x=4

{ 3(x+y) = 24

b) { 3x - 1= y -2

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

Answer 1

a) {y-x=4

    { 3(x+y) = 24

 

y=4+x

 

3(x+4+x) = 24

3x+12+3x = 24

6x = 24-12

6x = 12

x=2

 

y=4+2

y=6

 

 

b) { 3x - 1= y -2

    { 4x - 3= -2 (y-2 )

 

y=3x-1+2

y=3x+1

 

4x-3= -2(3x+1-2)

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

10x = 5

x= 0,5

 

y=3*0,5 + 1

y=2,5

Answer 2

a)

{y-x= 4
{3(x+y) = 24

{y-x = 4 | *3
{3x + 3y = 24

{3y - 3x = 12
{3y + 3x = 24
-----------------
6y = 36 | :6
y = 6 

6-x = 4 |-6
-x = -2 | *(-1)

x = 2

 

{3x - 1 = y-2
{4x - 3 = -2(y-2)

{3x - y = -1
{4x-3 = -2y +4

{3x-y = -1 | *2
{4x + 2y = 7

{6x - 2y = -2
{4x + 2y = 7
-----------------
10x = 5 | :10
x = 0,5 

 

 3* 0,5 - 1 = y-2
0,5 = y -2 | +2
y = 2,5