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![class=](https://pl-static.z-dn.net/files/def/8b6e886591f7df89a0435730a1324446.jpg)
Odpowiedź:
10x - 15 - x + 7 = 8 + 2x - 5x + 20
9x - 8 = 28 - 3x
12x = 36
x = 3
10x - 15 - x + 7 = 8 + 2x - 5x + 20
9x - 8 = 28 - 3x
12x = 36/:12
x = 3