Question

va rog mult dau 20 de puncte ​

Answer 1

Răspuns:

1) x + y = 4

2x + y = 7

y = 4 - x

2x + 4 - x = 7

y = 4 - x

x + 4 = 7

x= 7 - 4

x = 3 ; y = 1

2) x +y = 6

x + 4y = 21

x=6 - y

6-y + 4y =21

6 + 3y = 21

3y = 21 - 6

y = 15:3

y = 5

x = 1

3) 2x + 3y = 10

x - y=0

x=y

2y + 3y = 10

y = 2

x = 2

4) 2x + y = 12

x - 3y = -1

y = 12 - 2x

x - 3(12-2x) =-1

x - 36 + 6x = -1

7x = 35

x = 5

y = 12 - 10

y = 2

5) -x + y = 4

5x + 2y=8

y=4+x

5x + 2(4+x) = 8

x = 0

y = 0

6) -3x + 4y = -6

2x + y = 4

y= 4 - 2x

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

-3x + 16 - 8x = -6

11x = -22

x = -2

y = 0

Answer 2

Tema este mai jos in poza