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2 years ago

How many 7 digit phone numbers are there assuming the first digit can't be a 0 or a 1?

1 answer:

7 0

The first digit can be any one of the numbers 2-9 That a total of 8 numbers.

The next 6 digits can be any permutation of 6 from the numbers 0 to 9.
(10 numbers)

nPr = n! / r!

so here we have 10P6 = 10! / 6! = 10*9*8*7 = 5040

So final answer is 8 * 5040 = 40,320

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How do I find the value of X

sesenic [268]

You could either:
a) Use the Pythagorean Theorem
b) Use Sine/Cosine/Tangent Inverse to find one of the angles, and then use that angle to find x.

5 0

3 years ago

Read 2 more answers

Meredith is playing games at an arcade to earn tickets that she can exchange for a prize. She has 250 tickets from a previous vi

Nataly_w [17]

Considering the definition of equation, the number of games Meredith need to play is 12.

<h3>What is an equation</h3>

An equation in mathematics is defined as an equality established between two expressions, in which there may be one or more unknown values, called unknowns, in addition to certain known data.

The unknown or unknowns represent the number (or numbers), if any, that make the equality true. This unknown number or numbers represent the solution of the equation. So when changing the unknown or unknowns by the solution, the equality must be true.

<h3>Solution in this case</h3>

Meredith is playing games at an arcade to earn tickets that she can exchange for a prize. This is represented by:

y=6x + 250

where:

x represents the number of games Meredith plays.
y represents the number of tickets she needs for the prize.

Meredith needs 322 tickets to exchange for the prize she wants. This is, y=322.

Replacing in the expression y=6x + 250:

322= 6x + 250

Solving taking into account that:

When a value you are adding is passed to another side of the equation, this value will be subtracting.
If a value is multiplying it goes to the other side of the equation by dividing.

322 - 250=6x

72= 6x

72÷6= x

Finally, the number of games Meredith need to play is 12.

Learn more with this problem:

brainly.com/question/15564756

#SPJ1

7 0

1 year ago

Please help!! What is the solution to the quadratic inequality? 6x2≥10+11x

fredd [130]

Answer:

The solution of the inequation $6\cdot x^{2} \geq 10 + 11\cdot x$ is $\left(-\infty,-\frac{2}{3}\right]\cup\left[\frac{5}{2},+\infty\right)$ .

Step-by-step explanation:

First of all, let simplify and factorize the resulting polynomial:

$6\cdot x^{2} \geq 10 + 11\cdot x$

$6\cdot x^{2}-11\cdot x -10 \geq 0$

$6\cdot \left(x^{2}-\frac{11}{6}\cdot x -\frac{10}{6} \right)\geq 0$

Roots are found by Quadratic Formula:

$r_{1,2} = \frac{\left[-\left(-\frac{11}{6}\right)\pm \sqrt{\left(-\frac{11}{6} \right)^{2}-4\cdot (1)\cdot \left(-\frac{10}{6} \right)} \right]}{2\cdot (1)}$

$r_{1} = \frac{5}{2}$ and $r_{2} = -\frac{2}{3}$

Then, the factorized form of the inequation is:

$6\cdot \left(x-\frac{5}{2}\right)\cdot \left(x+\frac{2}{3} \right)\geq 0$

By Real Algebra, there are two condition that fulfill the inequation:

a) $x-\frac{5}{2} \geq 0 \,\wedge\,x+\frac{2}{3}\geq 0$

$x \geq \frac{5}{2}\,\wedge\,x \geq-\frac{2}{3}$

$x \geq \frac{5}{2}$

b) $x-\frac{5}{2} \leq 0 \,\wedge\,x+\frac{2}{3}\leq 0$

$x \leq \frac{5}{2}\,\wedge\,x\leq-\frac{2}{3}$

$x\leq -\frac{2}{3}$

The solution of the inequation $6\cdot x^{2} \geq 10 + 11\cdot x$ is $\left(-\infty,-\frac{2}{3}\right]\cup\left[\frac{5}{2},+\infty\right)$ .

3 0

3 years ago

Solve for d 2 + d = 2 - 3 (d - 5) -2

Kobotan [32]

Answer:

3.25

Step-by-step explanation:

2 + d = 2 - 3 (d - 5) -2

d= -3d+15-2

4d=13

d= 13/4= 3.25

5 0

3 years ago

Read 2 more answers

Giovani solves a system of equations algebrically he concludes that the lines are parallel which could be the final of his solut

kenny6666 [7]

Answer:

If the lines are parallel, final form of his solution is

b) -5 = -5+1

Step-by-step explanation:

As the options are not given in the question and the question is incomplete, lets complete the question first.

Giovani solves a system of linear equations algebrically, he concludes that the lines are parallel. Which could be his final answer.

a) -5 = -5

b) -5 = -5+1

c) 11 = 11

d) 5 = 5

We know that parallel lines never cross at any point, there is no intersection point, which eventually means that there is no solution to the given equations. A system of equations which have no solution is called an inconsistent system of equations, and it graphs the parallel line.

From the options we can clearly see that only (b) has no solution, while all the rest of the options have solutions. Hence, -5 = -5+1 represents parallel lines.

3 0

2 years ago