Question

What is the solution set of 2x 2 + x = 15?
{3, -5/2}
{-3, 5/2}
{2, -3/2}

Answer 1

2x 2 + x = 15
2x 2 + x -15 = 0
(2x - 5)(x+3) = 0

2x-5=0
x = 5/2

x+3=0
x=-3

answer {-3, 5/2}
(second choice)

Answer 2

Answer:

{-3, 5/2}

Hence the Second Option