Which equation has the solutions x= square root 5? x2 + 2x + 4 = 0
x2 - 2x + 4 = 0
x2 + 2x – 4 = 0
x2 - 2x - 4 = 0

How do you solve

5

x

2

−

2

x

+

4

=

0

by quadratic formula?

=>Explanation:

Solve by quadratic formula:

5

x

2

−

2

x

+

4

=

0

is a quadratic equation in standard form:

a

x

2

+

b

x

+

c

, where

a

=

5

,

b

=

−

2

, and

c

=

4

.

quadratic formula:

x

=

−

b

±

√

b

2

−

4

a

c

2

a

Substitute the values for

a

,

b

,

and

c

into the formula.

x

=

−

(

−

2

)

±

√

(

−

2

)

2

−

4

⋅

5

⋅

4

2

⋅

5

Simplify.

x

=

2

±

√

4

−

80

10

x

=

2

±

√

−

76

10

Prime factorize the number of the square root.

x

=

2

±

i

√

2

×

2

×

19

10

Simplify.

x

=

2

±

2

i

√

19

10

Reduce.

x

=

1

±

i

√

19

5

Solutions for

x

.

x

=

1

+

i

√

19

5

,

x

=

1

−

i

√

19

5

whats the question?

step-by-step explanation:

b: |12 – x| ≤ 0.25

step-by-step explanation:      

let x be the possible lengths in inches, of the ribbons jaime cut.

we have been given that jaime is cutting strips of ribbon for a project. he tries to cut each piece to be 12 inches long, but sometimes he cuts it too long or too short by as much as 0.25 inch.  

we can represent this information in an inequality as:

by the definition of absolute value function we will get,

upon combining our inequalities we will get,

therefore, the inequality   describes all the possible lengths (x), in inches, of the ribbons jaime cut.

step-by-step explanation: