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3 years ago

Which equation could be solved using this application of the quadratic formula?

Mathematics

1 answer:

Alex_Xolod [135]3 years ago

8 0

Answer:

C. x^2 + 2x - 1 = 3

Step-by-step explanation:

The standard form of a quadratic equation is

ax^2 + bx + c = 0

We need to use the quadratic formula and the given expression to find the values of a, b, and c.

The quadratic formula is

$x = \dfrac{-b \pm \sqrt{b^2 - 4ac}}{2a}$

Where the formula has -b, the problem has -2, so b = 2.

Now we have

ax^2 + 2x + c = 0

In the denominator, where the formula has 2a, the problem has 2(1), so a = 1.

Now we have

x^2 + 2x + c = 0

Inside the root, the quadratic formula has -4ac. the problem shows -4(1)(-4). Since we already know that a = 1, then c = -4.

Now we have

x^2 + 2x - 4 = 0

Let's look at choice A.

x^2 + 1 = 2x - 3

Subtract 2x from both sides. Add 3 to both sides.

x^2 - 2x + 4 = 0 This is not it!

Let's look at choice B.

x^2 - 2x - 1 = 3

Subtract 3 from both sides.

x^2 - 2x - 4 = 0 This is not it!

Let's look at choice C.

x^2 + 2x - 1 = 3

Subtract 3 from both sides.

x^2 + 2x - 4 = 0 This is it!

Answer: C. x^2 + 2x - 1 = 3

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3 years ago

A family pass to the amusement park costs $54 Using the Distributive Property,write an expression that can be used to fine the c

ruslelena [56]

The distributive property is: a(b + c) = ab + ac. In this expression, the example would be 8(54 + 0) = (8 x 54) + (8 x 0). The cost of eight family passes is therefore equal to 8 x 54. $432 is the answer.

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3 years ago

How do I find each measure? Please I need answers ASAP it's due at 1:50

Norma-Jean [14]

Answer:

Angle CAD is 44 degrees

Angle ACD is 44 degrees

Angle ACB is 136 degrees

Angle ABC is 22 degrees

Explanation:

29. Triangle ADC is an isosceles triangle because it has two equal sides.

If segments AD and DC are congruent, then segment AC is the base and the base angles of an isosceles triangle are equal.

Let x be angle CAD.

Let's go ahead x;

$\begin{gathered} 92+x+x=180\text{ (sum of angles in a triangle)} \\ 92+2x=180 \\ 2x=180-92 \\ 2x=88 \\ x=\frac{88}{2} \\ \therefore x=44^{\circ} \end{gathered}$

Therefore, measure of angle CAD is 44 degrees.

30. Measure of angle ACD is 44 degrees (Base angles of an isosceles triangle are equal)

31. Let angle ACB be y,

Let's go ahead and find measure of angle ACB;

$\begin{gathered} 44+y=180\text{ (angles on a straight line)} \\ y=180-44 \\ \therefore y=136^{\circ} \end{gathered}$

So measure of angle ACB is 136 degrees.

32. Let angle ABC be z.

Triangle ACB is also an isosceles triangle so the base angles are the same.

Let's go ahead and find z;

$\begin{gathered} 136+z+z=180_{}\text{ (sum of angles in a triangle)} \\ 138+2z=180 \\ 2z=180-136 \\ 2z=44 \\ z=\frac{44}{2} \\ \therefore z=22^{\circ} \end{gathered}$

So measure of angle ABC is 22 degrees.

3 0

1 year ago

A cylinder has a diameter of 6 feet. the volume of the cylinder is 36/5π cubic feet.

Anton [14]

Answer:

Height of cylinder is $\frac{4}{5}\ ft$ .

Step-by-step explanation:

Diameter of cylinder, D = 6 feet

Relation between Radius, R and diameter, D is given by:

$R = \dfrac{D}{2}$

So, radius, R = $\frac{6}{2} \Rightarrow 3$ feet

Let height of cylinder be $h$ feet.

Formula for volume of cylinder is given by:

$V = \pi R^{2} H$

Where, R is the radius of base of cylinder

and H is the height of cylinder

We are given that,

$V = \dfrac{36 \pi}{5} ft^{3}$

Using formula for volume, $V = \pi R^{2} H$

$\dfrac{36\pi}{5} = \pi \times 3^{2} \times h\\\Rightarrow \dfrac{36\pi}{5} = \pi \times 9 \times h\\\Rightarrow h = \dfrac{4}{5} ft$

Hence, Height of cylinder is $\frac{4}{5}\ ft$ .

7 0

3 years ago

the hardcover version of a book weighs 7 ounces while its paperback version weighs 5 ounces. Forty-five copies of the book weigh

Nuetrik [128]

Keywords:

System of equations, variables, hardcover version, paperback version, books

For this case we must construct a system of two equations with two variables. Let "h" be the number of hardcover version books, and let "p" be the number of paperback version books. If the hardcover version of a book weighs 7 ounces and the paperback version weighs 5 ounces, to reach a total of 249 ounces we have:

$7h + 5p = 249$ (1)

On the other hand, if there are Forty-five copies of the book then:

$h + p = 45$ (2)

If from (2) we clear the number of books paperback version we have:

$p = 45-h$

As each paperback version book weighs 5 ounces, to obtain the total weight of the paperback version books, represented by "x" in the table shown, we multiply $5 * p = 5 (45-h)$

So, $x = 5 (45-h)$

Answer:

$x = 5 (45-h)$

Option D

8 0

3 years ago

Read 2 more answers