Question

Zadnie 4/c http://zadane.pl/files/d5a/4bc59e0209e26ad9ee7f1ffce76b5006.jpg

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Answer 1

zad. 4

a)

{6x+6y=10y  /-6y

{y-x=0,5  /-y

 

{6x=4y

{x=0,5-y

 

podkładamy zamiast x będzie 0,5-y czyli 6(0,5-y)=3-6y

{3-6y=4y  /+6y

{x=0,5-y

 

{3=10y  /:10

{x=0,5-y

 

{y=0,3

{x=0,5-0,3

 

{x=0,2

{y=0,3

Answer 2

2(2x-y)+3(x+3y)=42

5(x+3y)-8(2x-y)=-32

 

4x-2y+3x+9y=42

5x+15y-16x+8y=-32

 

7x+7y=42 

-11x+23y=-32

 

77x+77y=462

-77x+161y=-224

 

77y+161y=462-224

238y=238

y=1

 

7x+7*1=42

7x=35

x=5

 

x=5

y=1

 

Pozdrawiam.