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3 years ago

Simplify: 2(xy - 7) = [?] x = -1 and y = 3

Mathematics

1 answer:

fiasKO [112]3 years ago

5 0

Answer:2(xy-7)= -20

Step-by-step explanation:

Plug in -1 for x and 3 for 3, as the question says that x and y represent those values.

2(xy-7) = ?

2((-1)(3) - 7) = ?

2(-3-7)=?

2(-10)

-20

2(xy - 7) = -20

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lions [1.4K]

Step-by-step explanation:

$\angle AOB$ and $\angle BOC$ are linear pair angles.

$\therefore m\angle AOB + m\angle BOC = 180° \\ \therefore \: 3x + 124 \degree + 6x + 29 \degree = 180° \\ \therefore \: 9x + 153 \degree = 180° \\ \therefore \: 9x = 180° - 153 \degree \\ \therefore \: 9x = 27 \degree \\ \therefore \:x = \frac{27 \degree }{9} \\ \huge \pink{ \boxed{\therefore \:x =3 \degree }} \\ \\ \because \: m\angle BOC =6x + 29 \degree \\ \therefore \: m\angle BOC =6 \times3 \degree + 29 \degree \\ \therefore \: m\angle BOC = 18\degree + 29 \degree \\ \\ \huge \red{ \boxed{\therefore \: m\angle BOC = 47 \degree }}$

5 0

3 years ago

Following are heights, in inches, for a sample of college basketball players. 78 83 82 78 78 80 81 79 79 83 77 78 84 82 80 80 82

blagie [28]

The mean height of the basketball players is 80.3 inches

For given question,

we have been given the list of heights, in inches, for a sample of college basketball players.

We need to find the mean height of the basketball players.

We know that, for given sample of data

mean = sum of all observations ÷ total number of observation

First we find the sum of given heights.

78 + 83 + 82 + 78 + 78 + 80+ 81 +79+ 79 +83+ 77 +78+ 84+ 82+ 80+ 80 +82+ 84+78+ 80 = 1606

Total number of observations = 20

Using the formula of mean,

⇒ mean height = 1606/20

⇒ mean height = 80.3 inches

Therefore, the mean height of the basketball players is 80.3 inches

Learn more about the mean here:

brainly.com/question/6813742

#SPJ4

3 0

1 year ago

Describe and correct the error(s) made in each of the problems below.

ladessa [460]

Answer:

$\displaystyle \frac{1-x}{(5-x)(-x)} =-\frac{x-1 }{ x(x-5)}$

$\displaystyle \frac{5}{s}\times \frac{2}{5} =\frac{2}{s}$

Step-by-step explanation:

<u>Errors in Algebraic Operations </u>

It's usual that students make mistakes when misunderstanding the application of algebra's basic rules. Here we have two of them

When we change the signs of all the terms of a polynomial, the expression must be preceded by a negative sign
When multiplying negative and positive quantities, if the number of negatives is odd, the result is negative. If the number of negatives is even, the result is positive.
Not to confuse product of fractions with the sum of fractions. Rules are quite different

The first expression is

$1-x / (5-x)(-x)=x-1 / x(x-5)$

Let's arrange into format:

$\displaystyle \frac{1-x}{(5-x)(-x)} =\frac{x-1 }{ x(x-5)}$

We can clearly see in all of the factors in the expression the signs were changed correctly, but the result should have been preceeded with a negative sign, because it makes 3 (odd number) negatives, resulting in a negative expression. The correct form is

$\displaystyle \frac{1-x}{(5-x)(-x)} =-\frac{x-1 }{ x(x-5)}$

Now for the second expression

$5/s+2/5=2/s$

Let's arrange into format

$\displaystyle \frac{5}{s}+\frac{2}{5} =\frac{2}{s}$

It's a clear mistake because it was asssumed a product of fractions instead of a SUM of fractions. If the result was correct, then the expression should have been

$\displaystyle \frac{5}{s}\times \frac{2}{5} =\frac{2}{s}$

6 0

3 years ago

How do I do number 4?

Galina-37 [17]

What are you trying to find?

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3 years ago

Read 2 more answers

A square rug has an area of 1.44m ^2. Find the length of a side of the rug.

Juli2301 [7.4K]

the answer is 42.77...........................................

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3 years ago