zpět
x + y = 5
x – y = 1
x = 5 – y
5 – y – y = 1
5 – 2y = 1
-2y = -4
y = 2
x – 2 = 1
x = 3
ZK:
L1: 2 + 3 = 5
P1: 5
L1 = P1
L2: 3 – 2 = 1
P2: 1
L2 = P2