Odpowiedzi

2009-11-04T20:58:25+01:00
X + y = 20
x - y = -40
----------------
x = 20 -y
20 -y - y = -40
-2y = -40 -20
-2y = -60 I : (-2)
y = 30
x = 20 - y = 20 -30 = - 10
Odp.Te liczby ,to -10 i 30.
2009-11-04T21:01:52+01:00
X+y=20
x-y=-40
x=20-y
20-y-y=-40
-2y=-40-20
-2y=-60I:(-2)
y=30
x=20-y=20-30=-10
2009-11-04T21:09:41+01:00
X + y = 20
y - x = -40
y = -40 + x
podstawiamy dane y do x+y = 20
x + (-40) +x = 20
x - 40 + x = 20
2x = 20 + 40 = 60
x = 30
y = -40 + 30
y = -10

Sprawdzamy:
x + y = 20; 30 + (-10) = 30 -10 = 20
y - x = -40; -10 - 30 = -40
Odp. x = 30; y = -10