Question

Solve 2x2 + x = 15.

x = −5 and x = 5
x = three over two and x = −5
x = 15 and x = −2
x = five over two and x = −3

Answer 1

-3 and 2.5

Answer 2

Those aren't answers?

Answer 3

Oh
Nevermind

Answer 4

to solve this, rewrite it

\[2x^2 + x - 15 = 0\]

this can be factored or solved using the general quadratic formula

for a quadratic \[ax^2 + bx + c = 0\]

multiply a and c so you have 2 * -15 = -30

find the factors that add to 1, the larger factor is positive, so 6 and -5

next write it in factored form

(ax + factor 1)(ax + factor 2)
-------------------------
a

so your problem becomes

\[\frac{(2x + 6)(2x - 5)}{2} = 0\]

remove any common factors \[\frac{2(x +3)(2x -5)}{2} = (x+3)(2x -5) = 0\]

so you can solve

x + 3 = 0 and 2x - 5 = 0

to get the solutions