Odpowiedzi

2010-01-20T16:51:51+01:00
A) x+3y=3
x-y=5

x=3-3y
3-3y-y=5

x=3-3y
-4y=5-3

x=3-3y
-4y=2/:(-4)

x=3-3y
y=2/4

y=2/4 [w ułamku]
x=3-3*2/4

y=2/4
x=3-2 2/4

y=2/4
x=2/4

b) 2x-y=10
x+5y=-17

2x-10=y
x+5*(2x-10)=-17

2x-10=y
x+10x-50=-17

2x-10=y
11x=-17+50

2x-10=y
11x=33/11

x=3
2*3-10=y

x=3
y=-4

d) 4a-2=b
3a+7b=1,5

b=4a-2
3a+7*(4a-2)=1,5

b=4a-2
3a+28a-14=1,5

b=4a-2
31a=1,5+14

b=4a-2
31a=15,5/31

b=4a-2
a=15,5/31 [w ułamku]

a=15,5/31
b=4*15,5/31-2

a=15,5/31
b=0
2010-01-20T17:04:09+01:00
A) x+3y=3
x-y=5

x=3-3y
x-y=5

x=3-3y
3-3y=5

x=3-3y
-3y=5-3

x=3-3y
-3y=2 |:(-3)

x=3-3y
y=-²/₃

x=3- 3*(-²/₃)
y=-²/₃

x=3-(-2)
y=-²/₃

x=5
y=-²/₃

b) 2x-y=10
x+5y=-17

-y=10-2x |:(-1)
x+5y=-17

y=-10+2x
x+5y=-17

y=-10+2x
x+5(-10+2x)=-17

y=-10+2x
x-50+10x=-17

y=-10+2x
11x=33 |:11

y=-10+2x
x=3

y=-10+2*3
x=3

y=-4
x=3

d) 4a-2=b
3a+7b=1,5

b=4a-2
3a+7b=1,5

b=4a-2
3a+7(4a-2)=1,5

b=4a-2
3a+28a-14=1,5

b=4a-2
31a=15,5 |:31

b=4a-2
a=0,5

b=4*0,5-2
a=0,5

b=0
a=0,5