Odpowiedzi

2009-12-10T16:10:20+01:00
A)
8a+9b=36 → 8a-108=36 → 8a=144 /÷8 → a=18
a-16b=210 /∧(-8)

8a+9b=36
+ -8a+128b=-1680
--------------------
137b=-1644 /÷137
b=-12
a=18


b)
4y+2x=10 /∧ -2
3x+8y=10 → 30+8y=10 → 8y=-20 /÷8 → y=-2,5

-4x-8y=-20
+ 3x+8y=10
-------------------
-x=-10 /∧ -1
x=10
y=2,5

c)
5a+8b=14 /∧ 4
4a+3b=1 /∧ -5 → 4a+9=1 → 4a=-8 /÷ 4 → a=-2

20a+32b=56
+ -20a-15b=-5
---------------------
17b=51 /÷17
b=3
a=-2