Question

Matematyka z + Zad.4 str.99 Rozwiąż układy równań a) 3x=12 x-y=1 b) 5y=2 x+y=2 2/5 c) 4y-x=6 17y=0 d) a=b 2a+b=9 e) u=4v 5u-v=10 f) 3r=s 3r+s=24

Na dzisiaj

Answer 1

A).
{3x=12/:3
{x-y=1

{x=4
{x-y=1

{x=4
{4-y=1

{x=4
{-y= -3*(-1)

{x=4
{y=3

b).
{5y=2/:5
{x+y=2 2/5

{y=2/5
{x+2/5=2 2/5

{y=2/5
{x=2 2/5-2/5

{y=2/5
{x=2

c).
{4y-x=6
{17y=0/:17

{4y-x=6
{y=0

{4*0-x=6
{y=0

{-x=6/*(-1)
{y=0

{x= -6
{y=0

d).
a=b
{2a+b=9

{a=b
{2b+b=9

{a=b
{3b=9/:3

{a=b
{b=3

{a=3
{b=3

e).
{u=4v
{5u-v=10

{u=4v
{5*4v-v=10

{u=4v
{20v-v=10

{u=4v
{19v=10/:19

{u=4v
{v=10/19

{u=4*10/19
{v=10/19

{u=40/19
{v=10/19

f).
{3r=s
{3r+s=24

{3r=s
{s=24-3r

{3r=24-3r
{s=24-3r

{3r+3r=24
{s=24-3r

{6r=24/:6
{s=24-3r

{r=4
{s=24-3*4

{r=4
{s=24-12

{r=4
{s=12

Answer 2

a) 3x=12 x-y=1
x=4
4-y=1

x=4
-y=1-4

x=4
y=3


b) 5y=2 x+y=2 2/5

y=2/5
x + 2/5 = 2 2/5

Y=2/5
x=2


c) 4y-x=6 17y=0

y=0
-x=6

y=0
x=-6

d) a=b 2a+b=9

a=b
2a+a=9

a=b
3a=9

a=b
a=3

a=3
b=3

e) u=4v 5u-v=10

u=4v
5*4v-v=10

u=4v
20v -v =10

u=4v
19v =10

u=4v
v = 10/19

u= 40/19
v= 10/19



f) 3r=s 3r+s=24

3r=s
s+s=24

3r=s
2s=24

3r=s
s=12

3r=12
s=12

r=4
s=12