User talk:عماد فلسفی

$$ 1^2 = 1 \!\,$$

$$-1^2 = 1 \!\,$$

$$\sqrt{1} = \pm1 \,$$

$$\ y + 2 = y \,$$

$$\ y - y + 2 = 0 \,$$

$$\ y - y = - 2 \,$$

$$ \sqrt{1} - \sqrt{1} = - 2 \,$$

$$ +1 - (+1) = - 2 = False \,$$

$$ +1 - (-1) = - 2 = False \,$$

$$ -1 - (+1) = - 2 = True \,$$

$$ -1 - (-1) = - 2 = False \,$$