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3 years ago

What number must be added to 15,-6, and 12 to have a mean of 5? Explain.

Mathematics

1 answer:

Genrish500 [490]3 years ago

3 0

You need to add a -1

We can find this by setting up the equation like so

x + (-6) + 12 + 15 / 4 = 5

x + 21 = 20

x = 20 -21

x = -1

Now if we insert -1 where x is located in the equation, you will get a means of 5

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A textbook store sold a combined total of 426 math and sociology textbooks in a week. The number of math textbooks sold was 88 m

SOVA2 [1]

Let m and s be the number of math and sociology books sold respectively.

m=s+88 we are also told that:

m+s=426, using m found above in this equation gives you:

s+88+s=426 combine like terms on left side

2s+88=426 subtract 88 from both sides

2s=338 divide both sides by 2

s=169, since m=s+88

m=169+88=257

So 257 math and 169 sociology textbooks were sold.

8 0

3 years ago

A triangular pyramid has a base with an area of 43 cm squared and lateral faces with bases of 10 cm and heights of 8.6 cm. What

Jet001 [13]

Answer:

The total surface area of triangular pyramid is 172 cm squared

Step-by-step explanation:

Triangular pyramid:

Number of faces 4.
Number of vertices of a triangular pyramid is 6.
The volume is $\frac13 AH$ . A= area of the pyramid's base and H= height of the pyramid.

The surface area of triangular pyramid B+L. B= area of base, L= area of lateral surface.

Given that, the area of the base is 43 cm squared. Lateral faces with bases of 10 cm and heights 8.6 cm.

The 3 sides of the triangular pyramid is triangle in shape.

The area of triangle is $\frac12 \times base \times height$ .

The lateral surface area of the triangular pyramid is

$=3(\frac12 \times base \times height)$

$=3(\frac12\times 10\times8.6)$ cm squared

=129 cm squared

The total surface area of triangular pyramid is

=Area of the base + lateral surface area

=(43+129) cm squared

=172 cm squared

8 0

4 years ago

Walter wants computer software that cost $129. He has $57 saved. If he saves a maximum of $15 a week, the following inequality c

Lina20 [59]

In this question, it is given that

Walter wants computer software that cost $129. He has $57 saved.

he saves a maximum of $15 a week, the following inequality can be used to find how many weeks it will take Walter to save enough money to buy the software.

$15x+57 \geq 129$

And we have to solve this inequality for x.

First we subtract 57 to both sides. And on doing so , we will get

$15x\geq 72$

Dividing both sides by 15.

$x \geq 4.8$ \

Correct option is A.

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3 years ago

Kory and two of his friends are going to rent a 3 bedroom apartment for $960 a month. The security deposit is $400 and the pet d

solmaris [256]

Answer:$773.33

Step-by-step explanation:

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3 years ago

How can you identify unit rate from a table, equation and graph

Zina [86]

Answer:

hiiii

Step-by-step explanation:

To find the unit rate, divide the numerator and denominator of the given rate by the denominator of the given rate.

(Table)

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To find the unit rate, divide the numerator and denominator of the given rate by the denominator of the given rate. So in this case, divide the numerator and denominator of 70/5 by 5, to get 14/1, or 14 students per class, which is the unit rate. ( Graph)

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3 years ago