For which equasion does the sum of the roots equal 3/4 and the product of the roots equal -2?

Question

(a)4x^2-8x+3=0
(b)4x^2+8x+3=0
(c)4x^2-3x-8=0
(d)4x^2+3x-2=0

Answer 1

For the general quadratic equation
ax²+bx+c=0
the sum of the roots is -b/a,
and the product of the roots is c/a.

So we look for an equation where
-b/a = 3/4 and
c/a = -2

(a) and (b) are rejected because c/a>0
for (c),
c/a = -8/4 = -2,
-b/a = -(-3)/4 = 3/4
So the answer is (c)