Question

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x+y=2

x-y=1

2x+y=5

4x-y==10

3x+2y=2

3x+y=1,5

Answer 1

1. x+y+x-y=2+1

2x=3

x= 3/2

x= 1.5

x+y=2

1.5+y=2

y=0.5

 

 

2. 2x+y=5

4x-y=10

 

2x+y+4x-y=5+10

6x=15

x=15/6

x=2.5

 

 

3. 3x +2y=2

3x+y=1.5

y=1,5-3x

 

3x+2(1,5-3x)=2

3x+3- 6x=2

3x-6x=2-3

-3x=-1/; -3

x= 1/3

 

 

 

Answer 2

x+y=2                                    

x-y=1     

 

x+y=2

x=1+y

 

1+y+y=2

x=1+y

 

2y=2-1

x=1+y

 

 2y=1

x=1+y

                                          

 y=1/2

x=1+1/2

 

y=1/2

x=1+y=1+1/2=1 1/2= 3/2

 

x=3/2

y=1/2

2x+y=5                                   

4x-y==10        

 

y=5-2x

4x-5+2x=10

 

y=5-2x

4x+2x=10+5

 

y=5-2x

6x=15

 

y=5-2x

x=15/6

 

y=5-2*15/6= 5-30/6= 5-5= 0

 

                                   

x=15/6 

y= 0

 

 

3x+2y=2                                       

3x+y=1,5

 

3x+2y=2 

y=1,5-3x

 

3x+2(1,5-3x)=2

y=1,5-3x

 

3x+3-6x=2

y=1,5-3x

 

3x-6x=2-3

y=1,5-3x

 

-3x= -1

y=1,5-3x

 

x=1/3

y=1,5-3x=1,5-3*1/3= 1,5-1= 0,5

 

x=1/3

y=0,5