Answer
Solutions:
$x=4$
$x=-\frac{7}{2}$
Work Step by Step
$2x^2-x-28=0~~$ ($a=2,b=-1,c=-28$)
$x=\frac{-b±\sqrt {b^2-4ac}}{2a}=\frac{-(-1)±\sqrt {(-1)^2-4(2)(-28)}}{2(2)}=\frac{1±\sqrt {225}}{4}=\frac{1±15}{4}$
$x=\frac{16}{4}=4$ or $x=\frac{-14}{4}=-\frac{7}{2}$
