delta.....................
![Delta class=](https://ro-static.z-dn.net/files/d77/4bf7b888a2b2c743cef910b57e55a02b.jpg)
3x² - 12 = 0
X² - 4 = 0
X² = 4
X² = ± 2
X = - 2
X = 2
X¹ = -2, x² = 2
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