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3 years ago

Solve the equation with substitution 3x-2y=9 Y=2x-7

1 answer:

3 0

$3x-2y=9 \\
y=2x-7 \\ \\
\hbox{substitute 2x-7 for y in the 1st equation:} \\
3x-2(2x-7)=9 \\
3x-4x+14=9 \\
-x+14=9 \ \ \ |-14 \\
-x=-5 \ \ \ |\times (-1) \\
x=5 \\ \\
y=2x-7=2 \times 5-7=10-7=3 \\ \\
\boxed{(x,y)=(5,3)}$

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School a has 18 staff and 225 students.

Pavel [41]

Answer:

School A

Step-by-step explanation:

School A has a ratio of 18/225 = 2/25 staff to students
School B has a ratio of 23/322 = 2/28 = 1/14 staff to students
Assuming that a better ratio means more staff per students School A has a better ratio

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3 years ago

1) Diego measured the number of cups of water in 15 bottles of various sizes. He

Ivan

Answer:

$8\frac{3}{4}$ cups.

Step-by-step explanation:

From the line plot made by Diego which represents bottle sizes in cups, we can see that the most common size is the bottle having 1¾ cups (there are 5 of this sizes).

If he poured all 5 of this bottle sizes in 1 container, he would have the following:

$1\frac{3}{4} * 5 = \frac{7}{4}*5 = \frac{35}{4}$

$= 8\frac{3}{4}$ cups.

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3 years ago

What is -2x-3=y in standard form

just olya [345]

<span>-2x-3=y in standard form
=
2x + y = -3

hope it helps</span>

6 0

4 years ago

Devon records 4 hours of reality shows on her DVR she records comedy shows for 3/8 of that amount of time. Devon watches all the

Alenkinab [10]

The number of half-hour sittings needed to watch all the shows by Devon is 11

<u>Solution:</u>

Given, Devon records 4 hours of reality shows on her DVR

she records comedy shows for 3/8 of that amount of time.

$\rightarrow \frac{3}{8} \text { of } 4 \text { hours } \rightarrow \frac{3}{8} \times 4 \rightarrow \frac{3}{2} \text { hours }$

Devon watches all the reality and comedy shows in half-hour sittings.

We have to find the number of half-hour sittings needed to watch all the shows

Now, number of half hour sittings is given as

$=\frac{\text { total time of videos }}{\text { time for hlaf hour sitting }}$

$\begin{array}{l}{=\frac{4 \text { hours for reality shows }+\frac{3}{2} \text { hours for comedy shows }}{\frac{1}{2} \text { hours for each sitting }}} \\\\ {=\frac{4+\frac{3}{2}}{\frac{1}{2}}=\frac{\frac{8+3}{2}}{\frac{1}{2}}=\frac{\frac{11}{2}}{\frac{1}{2}}=\frac{11}{2} \times \frac{2}{1}=11}\end{array}$

Hence Devon needs 11 sittings

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3 years ago

then difference between the cubes of two numbers is twice the value of the perfect square of a possitive Intiger

PSYCHO15rus [73]

There are many solutions. But what do you mean with a perfect square of a number. I thought a number IS a perfect square or not.

For example, the difference between 2² and 4² = 12, which is twice the number 6, which is √36

The difference between 2² and 6² = 32, which is twice the number 16, which is a perfect square.

So choose depending on your interpretation of the question... ;-)

8 0

3 years ago