а) (4х+3)^2 - 24x = 16x^2 + 24x + 9 -24x = 16x^2 + 9
x² + 25 = 54;
x² = 54 - 25;
x² = 29.
D(y): (x+4)(7-x)>=0
7x+28-4x-x2>=0
-x2-4x+28>=0 | : -1
x2+4x-28=0
x1=7;
x2=-4;
D(y): x>(-4)
x є -4; + ∞