He made a mistake in step #2. It seemed to be a trivial mistake because it involved signs, but it still had a great impact. Since step#2, his solution was already wrong.
Instead of
(-1)²-4(2)(-6) = 1 + 48 = 49
What he did is
(-1)²-4(2)(-6) = -1 + 48 = 47
9 is the answer because 1/3 = 3
Answer:
y = -1/3x + 5
Step-by-step explanation:
-1/3 is the slope because the line goes down 1 unit and right 3 units.
The y-intercept is 5 because that is where the line crosses the y-axis.
First step: x= ± √ 121
Second step and correct answer: x= ± 11
Because: x^2 = x= ± √