Question

como resolver: x²-7=4(x-2)

Answer 1

$x^{2} -7=4(x-2)\\ x^{2} -7=4x-8\\ x^{2} -7-4x+8=0\\ x^{2} +1-4x=0\\ x^{2} -4x+1=0\\\\ x=\frac{-(-4)\frac{+}{-}\sqrt{(-4)^{2}-4*1*1}}{2*1}\\\\ x=\frac{4\frac{+}{-}\sqrt{16-4}}{2}\\\\ x=\frac{4\frac{+}{-}\sqrt{12}}{2}\\\\ x=\frac{4\frac{+}{-}2\sqrt{3}}{2}\\\\ x=\frac{4+2\sqrt{3}}{2}\\\\ x=\frac{4-2\sqrt{3}}{2}\\\\ x_{1}=2-\sqrt{3}=0,26\\\\ x_{2}= 2+\sqrt{3}=3,73$