to solve this answer we use the quadratic formula
which is: x = -b +- square root b^2 - 4ac / 2a
a=9
b=15
c= -14
then simply plug in,
-15 +- square root 15^2 - 4(15)(-14)/2(9)
( Honestly you can use a website called desmos for quadratics but this is how you do it by hand)
so , x= -2.333, x= 0.667