(4х+5)(3-х)=х^2 - 2х
23x - 4x^2 +15 - 5x - x^2 +2x = 0
-5x^2 +20x+15 = 0
-x^2 + 4x +3=0
a = -1
b = 4
c = 3
(4х+5)(3-х)=х^2 - 2х
23x - 4x^2 +15 - 5x - x^2 +2x = 0
-5x^2 +20x+15 = 0
-x^2 + 4x +3=0
a = -1
b = 4
c = 3