Question

Can someone please help and explain this to me??
Decide which part of the quadratic formula tells you whether the quadratic equation can be solved by factoring.

−b b2 − 4ac 2a

Use the part of the quadratic formula that you chose above and find its value, given the following quadratic equation:

4x2 + 6x + 2 = 0

Answer 1

B squared minus 4ac

Answer 2

Here

Answer 3

The part b^2 - 2ac is called the discriminant.
If the discriminant is positive, the equation has 2 real solutions.
If the discriminant equals zero, there is one real solution.
If the discriminant is negative, there are no real solutions.

Answer 4

i guess you meant 4ac ? right ?....^

Answer 5

LOL, yes, correct.

Answer 6

Solving quadratic equations using quadratic formula?
Question 1 (Multiple Choice Worth 1 points)

What are the approximate solutions of 4x2 + 3 = −12x to the nearest hundredth?

x ≈ −3.23 and x ≈ 0.23

x ≈ −2.72 and x ≈ −0.28

x ≈ 0.28 and x ≈ 2.72<-----------

x ≈ −0.23 and x ≈ 3.23
For this one i keep getting 2.73 and 0.28 but the answer isnt there soo i just picked can you tell me if im right?
Question 2 (Multiple Choice Worth 1 points)

How can you tell when a quadratic equation has no real solutions?

when the radicand is negative<----------

when b in the quadratic formula is greater than the radicand

when the radicand equals zero

when the radicand is not a perfect square
For this one im almost positive its the answer i have the arrow pointed 2 but just want you to clarify it

Question 3 (Multiple Choice Worth 1 points)
For which value of x does the graph of y = 3x2 − 2x − 5 cross the x-axis?

-5/3

−1

−2

-3/5
For this one i just need help i have noo freaking clue how to do it...
Question 4 (Fill-In-The-Blank Worth 5 points)

Decide which part of the quadratic formula tells you whether the quadratic equation can be solved by factoring.

−b b2 − 4ac 2a

Use the part of the quadratic formula that you chose above and find its value given the following quadratic equation:

2x2 + 7x + 3 = 0

Numerical Answers Expected!

Answer for Blank 1:
Again this one i have no clue...

Question 6 (Multiple Choice Worth 1 points)

What are the exact solutions of x^2 = 4 −7x
I thought it was x=7x+-the square root of 33 divided by 2 i think im right but im not sure Anyone please help the major questions i need help with is 4 and 3 but please try to clarify if the one i think i know are right are right Thank you :)
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Answers
Krishnamurthy
Best Answer: 1).
4x^2 + 3 = -12x
4x^2 + 12x - 3 = 0
x = (-12 +/- sqrt 96)/8
x = (-3 +/- sqrt 6)/2
x = -0.275255
x = 2.72474
Answer:
x ≈ −2.72 and x ≈ −0.28

2).
How can you tell when a quadratic equation has no real solutions?
when the radicand is negative

3).
For which value of x does the graph of
y = 3x^2 - 2x - 5 cross the x-axis?
-1

4).
Decide which part of the quadratic formula tells you
whether the quadratic equation can be solved by factoring.
b^2 - 4ac

5).
Use the part of the quadratic formula that you chose above
and find its value given the following quadratic equation:
2x^2 + 7x + 3 = 0
b^2 - 4ac = 49 - 24 = 25

6).
x^2 = 4 - 7x
x^2 + 7x - 4 = 0
x = (-7 +/- sqrt 65)/2
Krishnamurthy · 3 years ago
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Jeff Aaron
1.
4x^2 + 3 = -12x
4x^2 + 12x + 3 = 0
x = (-12 +/- sqrt(12^2 - 4(4)(3))) / (2*4)
x = (-12 +/- sqrt(144 - 48)) / 8
x = (-12 +/- sqrt(96)) / 8
x = (-12 +/- sqrt(96)) / 8
x = -1.5 +/- sqrt(1.5)
x =~ -0.28 or -2.72

2.
How can you tell when a quadratic equation has no real solutions?
When the discriminant is negative (assuming the coefficients are real).

3.
3x^2 - 2x - 5 = 0
x = (-(-2) +/- sqrt((-2)^2 - 4(3)(-5))) / (2*3)
x = (2 +/- sqrt(4 + 60)) / 6
x = (2 +/- sqrt(64)) / 6
x = (2 +/- 8) / 6
x = (10 or -6) / 6
x = 5/3 or -1

6.
x^2 = 4 - 7x
x^2 + 7x - 4 = 0
x = (-7 +/- sqrt(7^2 - 4(1)(-4))) / (2*1)
x = (-7 +/- sqrt(49 + 16)) / 2
x = (-7 +/- sqrt(65)) / 2
x = -3.5 +/- sqrt(16.25)