Question

x^2+2x+3= -12+6x responda em IR

Answer 1

${x}^{2} + 2x + 3 = - 12 + 6x \\ {x}^{2} - 4x + 15 = 0 \\ d = { - 4}^{2} - 4 \times 1 \times 15 \\ d = 16 - 60 = - 44 \\ \\ x = \frac{4 \frac{ + }{ - } \sqrt{ - 44} }{2} \\ {i}^{2} = - 1 \\ \sqrt{ - 44} = \sqrt{44 \times ( - 1) }= 2\sqrt{11 {i}^{2} } \\ \\ x = \frac{4 \frac{ + }{ - } 2 \sqrt{11 {i}^{2} } }{2} = 2 \frac{ + }{ - } \sqrt{11 {i}^{2} } \\ \\ x_{1} = 2 + i\sqrt{11} \\ x_{2} = 2 - i\sqrt{11}$