[tex]7x-3x^2=85+2x^2+2x\\\\7x-3x^2-85-2x^2-2x =0\\\\ -5x^2+5x-85 =0\ \ | \ divide \ each \ term \ by \ (-5 ) \\\\ x^2-x+17=0\\\\\Delta = b^2-4ac = (-1)^2-4 \cdot 1 \cdot17 = 1-68 =-67\\\\Answer : \ \ If \Delta <0, \ then \ roots \ are \ imaginary \ and \ beyond \ the \ scope \ of \ this \ book [/tex]
