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2 years ago

Could someone explain number 18?

Mathematics

2 answers:

lora16 [44]2 years ago

6 0

It is going to be X= -19

Stolb23 [73]2 years ago

4 0

The process and answer are in the picture. If you’re satisfied, could you please give me a brilliant answer! :)

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Solve the quadratic equation by completing the square.

Step2247 [10]

Answer:

x1, x2 = 4.74 , -2.74

Step-by-step explanation:

To find the roots of a quadratic function we have to use the bhaskara formula

ax^2 + bx + c

x^2 - 2x - 13

a = 1 b = -2 c = -13

x1 = (-b + √ b^2 - 4ac)/2a

x2 =(-b - √ b^2 - 4ac)/2a

x1 = (2 + √ (2^2 - 4 * 1 * (-13)))/2 * 1

x1 = (2 + √ (4 + 52)) / 2

x1 = (2 + √ 56 ) / 2

x1 = (2 + 7.48) / 2

x1 = 9.48 / 2

x1 = 4.74

x2 = (2 - √ (2^2 - 4 * 1 * (-13)))/2 * 1

x2 = (2 - √ (4 + 52)) / 2

x2 = (2 - √ 56 ) / 2

x2 = (2 - 7.48) / 2

x2 = -5.48 / 2

x2 = -2.74

6 0

3 years ago

Graph f(x) =-2x^+16x-30 by factoring to find the solutions, then find the coordinates of the vertex, and the axis of symmetry. I

fredd [130]

Answer:

Observe attached image

Function zeros:

(3, 0), (5, 0)

Vertex:

(4, 2)

Axis of symmetry:

 $x =4$ 

Step-by-step explanation:

First factorize the function

$f (x) = -2x ^ 2 + 16x-30$

Take -2 as a common factor.

$-2(x ^ 2 -8x +15)$

Now factor the expression $x ^ 2 -8x +15$

You must find two numbers that when you add them, obtain the result -8 and multiplying those numbers results in 15.

These numbers are -5 and -3

Then we can factor the expression in the following way:

$f (x) = -2(x-5)(x-3)$

The quadratic function cuts the x-axis at x = 3 and at x = 5.

Now we find the coordinates of the vertex.

For a function of the form $ax ^ 2 + bx + c$ the x coordinate of its vertex is:

$x = \frac{-b}{2a}$

In the function $f (x) = -2x ^ 2 + 16x-30$

$a = -2\\b = 16\\c = 30$

Then the vertice is:

$x = \frac{-16}{2(-2)}\\\\x = 4$

The y coordinate of the symmetry axis is

$y = f (4) = -2 (4) ^ 2 +16 (4) -30\\\\y = 2$

The axis of symmetry is a vertical line that cuts the parabola in two equal halves. This axis of symmetry always passes through the vertex.

Then the axis of symmetry is the line

$x = 4$

The solutions and the vertice written as ordered pairs are:

Function zeros:

(3, 0), (5, 0)

Vertex:

(4, 2)

6 0

3 years ago

A girl is 18 years old and her brother is a third of her age. When the girl is 36 what would be the age of the brother?

ale4655 [162]

First we need to calculate how many years her brother has when she is 18. As text says he is:
18/3 = 6 years old

Now when she gains another 18 years (36-18=18) he will also gain those 18 years

When she is 36 he will have 6+18=24 years old

Answer is 24.

8 0

3 years ago

Read 2 more answers

You use a wedge that has a width of 2 cm and a slope length of 5.5 cm. What is the mechanical advantage of this wedge?

PIT_PIT [208]

Answer:

Option B. 2.75

Step-by-step explanation:

It has been given in the question that a wedge has a width of 2 cm and a slope of 5.5 cm.We have to calculate the mechanical advantage of the given wedge.

We know the formula to calculate the mechanical advantage of the wedge

Mechanical advantage = Length of slope/Thickness of the widest end

= 5.5÷2 = 2.75

Therefore the answer is option B. 2.75

6 0

3 years ago

Read 2 more answers

Olivia baked 45 mini-loaves of banana bread to be sliced for snacks at a craft fair. She will place an equal number of loaves in

allochka39001 [22]

Answer:

7 whole loaves of bread.

Step-by-step explanation:

Since there are total of 6 locations and each location needs to have the same number of whole loaves of bread we simply need to divide the number of mini-loaves of banana bread by the number of locations like so...

45 / 6 = 7.5

As we can see by the mathematical expression above 45 loaves of bread can be divided into 6, giving each location 7.5 loaves of bread but since each location needs only whole loaves then that would mean that each location would get 7 whole loaves of bread.

8 0

3 years ago