7 – 4x –x2 = 0


(i) 7 – 4x –x2 = 0
Sol. 7 – 4x – x2 = 0
 – x2 – 4x + 7 = 0
Multiplying throughout by –1, we get,
x2 + 4x – 7 = 0

Now it is in the standard form of ax2 + bx + c = 0