Question

The expression $ak^{2} + bk + c = 0$ has the positive value if.

• A. $ac < 0$
• B. $a^{2}k^{2} + abk + ac < 0$
• C. $4x^{2} - 20px + (25p^{2} + 15p - 66) = 0$
• D. $(4/5,\mspace{6mu} 2)$

Answer 1

Answer: (D)

$(4/5,\mspace{6mu} 2)$

Answer 2

$\mathbf{p}$

$\bullet \bullet$ $x^{2} + ax + b = 0$is a perfect square, therefore the given expression is positive if $\alpha^{3} + \beta^{3}$or $- (a^{3} + 3ab)$.