Since you cannot really factor this problem easily, we are going to resort to the quadratic formula!
x= -b+or- sqrt(b^2-4ac) / 2a
x=-17+ or - sqrt(17^2-4*50) /2
x=-17+ or - sqrt89 /2
Now we just need estimate sqrt 89 which is about 9.43 and I will not bother to show the step I did to estimate its about 9.43.
So x= -17+ or -9.43 /2
x= -26.43/2 or -7.57/2
x=-13.215 or -3.785
Round to nearest tenth digit.
x= -13.2 or -3.8
Hope this helps any questions just ask in the comments.