His mistake was in multiplying the 3 with the 12. He should have divided it from the 12 because that would have gotten rid of the 3 with the variable. It would also lead to the correct answer, which is b=4
The answer is 604.235378543
You can see by the image how did I get the answer
Here ya go. Hope this helps. Have a great day
Answer:
OR
Step-by-step explanation:
9x2−17x−85=0
For this equation: a=9, b=-17, c=-85
9x2+−17x+−85=0
Step 1: Use quadratic formula with a=9, b=-17, c=-85.