Solution:
1. Move all terms to one side
25{x}^{2}+40x+16-28=0
2. Simplify 25{x}^{2}+40x+16-28 to 25x2+40x−12
25{x}^{2}+40x-12=0
3. Apply the Quadratic Formulax=\frac{-40+20\sqrt{7}}{50},\frac{-40-20\sqrt{7}}{50}
4. Simplify solutions
x=-\frac{2(2-\sqrt{7})}{5},-\frac{2(2+\sqrt{7})}{5}
Done!
