21 + 5x = 41
5x = 41 - 21
5x = 20 | : 5
x = 4
6x - 5 - 4x = 7
6x - 4x = 7 + 5
2x = 12 | : 2
x = 6
Odpowiedź:
5x =51-21
5x= 30 /:5
6x-4x = 7+5
2x = 12 /:2
x=6