Question

Use the quadratic formula to solve x² + 8x + 9 = 0. What are the solutions to the equ ation? Round irrational solutions to the nearest tenth.

A. x = 1 and x=−9
B. X=-1and x=−8
C. x=−1.2 and X= -6.8
D. x=−6.6 and x=−1.4
ANSWER ASAP LIKE RIGHT NOW

Answer 1

it has to be d when you do the quadratic equation

Answer 2

First off, this is the quadratic formula:
x= -b +/- √b²-4ac
2a
(there's a division sign between the 2a)
Next, you would substitute each of the numbers in the equation for a, b, or c. For a, you would put it as 1. For b, you would say 8. For c you would say 9. Hopefully you get the pattern.
Then you plug in the numbers.
x=-8+/-√8²-4(1) (9)
2(1)
Then you would simplify.
8²=64
-4(1)(9)=-36.
64-36=28
√28≈5.3
So, you would end with
x=-8+/-5.3
2
Next, start with addition. Add -5.3 to the -8. That is -13.3. -13.3/2=-6.65. That is the first part of the answer.
Next, subtract. -8--5.3=-2.7. -2.7/2=-1.35.
The answers to problem is -6.65 and -1.35. Assuming your rounding your answers to the nearest tenth, your answer will be d. This is hard to explain in text, but I hope this makes sense.