81.7k views
1 vote
Harry is trying to solve the equation y = 2x2 − x − 6 using the quadratic formula. He has made an error in one of the steps below. Find the step where Harry went wrong. (1 point)

Step 1: x equals the negative of negative 1 plus or minus the square root of the quantity negative one squared minus 4 times 2 times negative six, end quantity, all over 2 times 2.

Step 2: x equals the negative of negative 1 plus or minus the square root of negative one plus forty-eight all over two times 2.

Step 3: x equals the negative of negative 1 plus or minus the square root of forty-seven all over two times 2.

Step 4: x equals 1 plus or minus the square root of forty-seven all over 4.

User Asanka
by
5.7k points

2 Answers

3 votes

Answer:

The above answer is correct.

Explanation:

I got it right on the test

User ATony
by
5.2k points
2 votes

Answer:

Step 2

Explanation:

The quadratic formula is given by
x=-b+-\frac{\sqrt{b^(2)-4ac } }{2a}

Our equation is y = 2x²-x-6

So here our a = 2, b = -1, and c = -6

We can now plug these numbers into our formula


x= -(-1) +-\frac{\sqrt{(-1)^(2)-4(2)(-6) } }{2(2)} = 1 +-(√(1+24) )/(4) = 1+-(√(25) )/(4)

Step 2 is incorrect because it states that "x equals the negative of negative 1 plus or minus the square root of negative one plus forty-eight all over two times 2."

The correct statement would be "x equals the negative of negative 1 plus or minus the square root of positive one plus forty-eight all over two times 2.", because the square of a negative is positive, resulting in a positive one.

Since this step is incorrect, the steps after are also incorrect, but Harry went wrong at Step 2

User Blgrnboy
by
5.1k points