Question

Решите уравнение. 3x^2-x-85=-11x^2

Answer 1

$3x^{2}-x-85=-11x^{2} \\ 14 x^{2} -x - 85=0 \\ D= b^{2} - 4ac= 1+4760= 4761 = 69^{2} x_{1} = \frac{ -b^{2}+ \sqrt{D} }{2a} = \frac{1+69}{28} = 2,5 \\ x_{2} = \frac{ -b^{2}- \sqrt{D} }{2a} = \frac{1-69}{28} = -2,4$