Answer:
[tex]\displaystyle x=\frac{-8\pm\sqrt{(8)^2-4(4)(-221)}}{2(4)}\ \text{; x = 6.5 and x = -8.5}[/tex]
Step-by-step explanation:
Subtract the right side of the given equation to put it into standard form:
4x² +8x -221 = 0
Then the coefficients used in the quadratic formula are ...
When these are filled into the form ...
[tex]\displaystyle x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}[/tex]
the result is as shown above.
