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kvv77 [185]
3 years ago
12

Solve by completing the square: x^2 + 7x + 4 = 0

Mathematics
1 answer:
Len [333]3 years ago
5 0

Answer:

x

2

+

7

x

−

4

=

0

Add  

4

to both sides of the equation.

x

2

+

7

x

=

4

To create a trinomial square on the left side of the equation, find a value that is equal to the square of half of  

b

.

(

b

2

)

2

=

(

7

2

)

2

Add the term to each side of the equation.

x

2

+

7

x

+

(

7

2

)

2

=

4

+

(

7

2

)

2

Simplify the equation.

Tap for more steps...

x

2

+

7

x

+

49

4

=

65

4

Factor the perfect trinomial square into  

(

x

+

7

2

)

2

.

(

x

+

7

2

)

2

=

65

4

Solve the equation for  

x

.

Tap for more steps...

x

=

±

√

65

2

−

7

2

The result can be shown in multiple forms.

Exact Form:

x

=

±

√

65

2

−

7

2

Decimal Form:

x

=

0.53112887

−

7.53112887

Step-by-step explanation:

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Which of the following is true of the discriminant for the graph below
aniked [119]

Answer:

Step-by-step explanation:

The discriminant is used to determine the number and nature of the zeros of a quadratic. If the discriminant is positive and a perfect square, there are 2 rational zeros; if the discriminant is positive and not a perfect square, there are 2 rational complex zeros; if the discriminant is 0, there is 1 rational root; if the discriminant is negative, there are no real roots.

The roots/solutions/zeros of a quadratic are where the graph goes through the x axis. Those are the real zeros, even if they don't fall exactly on a number like 1 or 2 or 3; they can fall on 1.32, 4.35, etc. They are still real. If the graph doesn't go through the x-axis at all, the zeros are imaginary because the discriminant was negative and you can't take the square root of a negative number. As you can see on our graph, the parabola never goes through the x-axis. Therefore, the zeros are imaginary because the discriminant was negative. Choice C.  Get familiar with your discriminants and the nature of quadratic solutions. Your life will be much easier!

4 0
3 years ago
What do I do? what's Ax??
Liono4ka [1.6K]

A=\left[\begin{array}{ccc}5&-4\\3&6\end{array}\right] \\\\A_x=\left[\begin{array}{ccc}12&-4\\66&6\end{array}\right]

|A_x|=\left|\begin{array}{ccc}12&-4\\66&6\end{array}\right|=(12)(6)-(66)(-4)=72+264=336

5 0
3 years ago
Jo's mother, Anne, is four times as old as Jo. In four years time, Anne will be three times as old as Jo. How old is Jo? (this i
pentagon [3]

Answer:

Jo's age = x = 8 years

Step-by-step explanation:

Let

Jo's age = x

Jo's mother, Anne's age = 4x

In four years time, Anne will be three times as old as Jo.

Jo's age =3( x + 4)

Jo's mother, Anne's age = 4x + 4

How old is Jo?

Equate Jo's age and his mother's age

3(x + 4) = 4x + 4

3x + 12 = 4x + 4

3x - 4x = 4 - 12

-x = - 8

Divide both sides by -1

x = 8

Therefore,

Jo's age = x = 8 years

8 0
3 years ago
Read 2 more answers
2(6 – x) – (9x + 2) = 4 + 8(x – 4)
Crank

Answer:

1.526

Step-by-step explanation:

12-2x-9x-2 = 4+8x-32

-11x+10 = 8x-28

-19x = -29

x = 1.526

4 0
3 years ago
Jaz has the following scores from a new game:
Marina86 [1]

Answer:

the mean of it all will increase

Step-by-step explanation:

3 0
2 years ago
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