Question

1) 4y - x = 6

17y = o

2) a = b

2a + b = 9

3) u = 4v

5u - v = 10

4) 3r = s

3r + s = 24

5) x + 3y = 3

x - y = 5

6) 2x - y = 10

2x + 5y = -17

Answer 1

1) 4y - x = 6

17y = o

4y=6+x

17y=0

y=1,5+x

17(1,5+x)=0

y=1,5+x

-22,5=17x

y=1,5+x

x=-1,5

y=0

x=-1,5

 

2) a = b

2a + b = 9

a=b

3b=9

a=b

b=3

a=3

b=3

3) u = 4v

5u - v = 10

u=4v

19v=10

u=4v

v=10/19

u=4* 10/19

v=10/19

u=40/19

v=10/19

4) 3r = s

3r + s = 24

3r=s

2s=24

3r=s

s=24

3r=24

s=24

r=8

s=24

5) x + 3y = 3

x - y = 5

x + 3y=3

x=5+y

5+4y=3

x=5+y

y=-0,5

x=4,5

y=-0,5

6)  2x - y = 10

2x + 5y = -17

x=5+0,5y

2(5+0,5y)+5y=-17

x=5+0,5y

10+6y=-17

x=5+0,5y

y=-4,5

x=2,75

y=-4,5

Answer 2

1) 4y - x = 6

17y = 0|:17

4y-x=6

y=0

4 * 0-x=6 |-0

y=0

-x=6 | (-1)

y= 0

x = -6

2) a=b

2a+b = 9 ( podstawiam same b )

2b+b=9

3b=9 |:3

b= 3

a=3

3) u=4v

5u-v=10

5*(4v-v)=10

20v-5v=10

15v=10|:15

v=2/3

u=4*2/3

v=2/3

u=2/3

4)3r=s

3r+s=24

3r+3r=24

6r=24|:6

r=4

s= 3*4

r=4

s=12

5) x+3y=3

x-y=5 |+y

y+5+3y=3

5+4y=3 |-5

4y= -2 |:4

y= -2

x= 5+(-2)

y=-2

x=3

6) nie umiem.!