Question

prosze o rozwiazanie:

a.7x-14yy=-21

3x-6y=1

b.3.4x-1.3=6

2.75+3=3.5-7

c.3x+9-2y-4=11/6

-3x-3.6=0.4+2y+2.4

d.2x-3y=4

3x-y=5

Answer 1

7x-14y=-21

3x-6y=1

 

7x = -21 + 14y /:7

3x - 6y = 1

 

x = -3 +2y

3(-3 + 2y) - 6y = 1

 

x = -3 + 2y

-9 +6y - 6y = 1

 

x= -3+2y

0= 10  ---> równanie sprzeczne

 

 

b.3.4x-1.3y=6
2.75x+3=3.5y-7

 

 

 

 

c.3x+9-2y-4=1 1/6
-3x-3.6=0.4+2y+2.4

 

3x -2y = 1 1/6 - 9 + 4

-3x - 2y = 0,4 + 2,4 + 3,6

 

3x - 2y = -23/6

-3x - 2y = 6,4

 

3x - 2y - 3x - 2y = -23/6 + 6,4

-4y = 2 34/60 /: (-4)

y= 77/120

 

-3x - 2y = 6,4

-3x - 2 * 77/120 = 6,4

-3x = 6,4 + 154/120

-3x= 7 /: (-3)

x= - 2 1/3

 

 

 

d.2x-3y=4

3x-y=5 /*(-3)

 

2x - 3y = 4

-9x +3y = -15

 

2x - 3y - 9x + 3y = 4-15

-7x = -11 /: (-7)

x= 1  4/7

 

2x - 3y = 4

2 * 1 4/7 - 3y = 4

-3y = 4 - 3 1/7

-3y = 28/7 - 22/7

-3y= 6/7 /: (-3)

y= - 2/7