Odpowiedzi

2009-12-07T22:32:59+01:00
A)
1+4y=3
y=1/2
x=1,5

b) niepoprawnie napisane ale:
3m-n=9
2m-5n= -11

n=9-3m
2m-5*(9-3m)=-11
2m+15m-45=-11
17m=34
m=34/17

n=9-3*34/17
n=9-6
n=3

c)też źle napisane
1 1 1
2009-12-07T22:36:43+01:00
A)x+3y=3
x-y=1
1+4y=3
y=1/2
x=1,5
b)3m=n=9
2m-5n= -11
nie wiem jak to zrobić..
c)5x=4-2y
4x=y-3
5x=4-2y
8x=2y-6

Najlepsza Odpowiedź!
2009-12-07T22:59:14+01:00
A)
x+3y=3
x-y=1 /+y

x+3y=3
x=1-y

1-y+3y=3 /-1
x=1-y

-y+3y=2
x=1-y

2y=2 /:2
x=1-y

y=1
x=1-1

y=1
x=0


3m-n=9 /-3m
2m-5n= -11

-n=9-3m /× -1
2m-5n= -11

n=-9 - (-3)m
2m-5n=-11

2m-5(-9-(-3)m)=-11
n=-9 - (-3)m

2m- (-45) - (-15)m = -11 /+(-45)
n=-9 - (-3)m

2m - (-15)m = - 11 +(-45)
n=-9 - (-3)m

17 m = -56

c)
5x=4-2y
4x=y=3

5x=4 - 2(4x)
4x=y=3

5x=4-8x /+8x
4x=y=3

13x=4 /÷13
4x=y=3

x=4/13