9.
[tex]f(x) = \sqrt{x^{2}-5x}\\\\\sqrt{x^{2}-5x} \geq 0\\\\x^{2}-5x \geq 0\\\\M. \ zerowe:\\\\x(x-5) = 0\\\\x = 0 \ \vee \ x - 5 = 0\\\\x = 0 \ \vee \ x = 5\\\\a > 0, \ ramiona \ paraboli \ skierowane \ do \ gory\\\\Dziedzina: \ x \in (-\infty,0\rangle \ \cup \ \langle5,\infty)\\\\Odp. \ A.[/tex]
10.
[tex]\frac{1}{4}-\frac{6-5x}{3} > 3x \ \ |\cdot12\\\\3-4(6-5x) > 36\\\\3-24+20x > 36x\\\\20x-36x > 21\\\\-16x > 21 \ \ /:(-16)\\\\x > -1\frac{5}{16}\\\\Odp. \ B. \ -2[/tex]
11.
[tex]f(x) = -(x+4)(x-10)\\\\f(x) = -(x^{2}-10x+4x-40)\\\\f(x) = -(x^{2}-6x-40)\\\\f(x) = -x^{2}+6x+40\\\\a = -1, \ b = 6, \ c = 40\\\\p = \frac{-b}{2a} = \frac{-6}{2\cdot(-1)} = \frac{-6}{-2} = 3\\\\q = f(p) = f(3) = -3^{2}+6\cdot3+40 = -9+18+40 =49\\\\a < 0, \ ramiona \ paraboli \ skierowane \ do \ dolu\\\\ZW = (-\infty, 49 \rangle\\\\Odp. \ B.[/tex]
