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3 years ago

A collection of quarters and dimes is worth $18.30. There are 111 coins in all.

1 answer:

7 0

We can set up a system of equations.

x + y = 111
0.25x + 0.10y = 18.30

x + y = 111

Subtract 'y' to both sides:

x = -y + 111

Plug in '-y + 111' for 'x' in the 2nd equation:

0.25(-y + 111) + 0.10y = 18.30

Distribute 0.25 into the parenthesis:

-0.25y + 27.75 + 0.10y = 18.30

Combine like terms:

-0.15y + 27.75 = 18.30

Subtract 27.75 to both sides:

-0.15y = -9.45

Divide -0.15 to both sides:

y = 63

Plug this back into any of the two equations to find the 'x' value.

x + y = 111

x + 63 = 111

Subtract 63 to both sides:

x = 48

So there are 48 quarters and 63 dimes.

You might be interested in

Dash offers and unlimited talk and texting plan for $80 per month AB&C charges $0.20 per text message and $55 for 1,000 min

mr_godi [17]

Answer:

Let's define x as the number of text messages send.

y as the number of 1,000 minutes talk per month.

(so we can write y = N/1000) where N is exactly the number of minutes that you talked that month.

> The equation for Dash is:

C1(x, y) = $80

>The equation for AB&C

C2(x,y) = $0,20*x + $55*y

> Horizon

C3(x,y) = $0.10*x + $75*y.

Now, which company you should go for?

Well, it depends on the values of x and y that you have.

if in your case you have x > y, you may want to go with Horizon, because the price per text is smaller.

if you usually talk, you may want to go with AB&C because the slope for y is smaller.

If you send a lot of texts and talk a lot, then Dash is the best option, because there is no dependence with the variables x, y

3 0

3 years ago

An elementary school is offering 3 language classes: one in Spanish, one in French,and one in German. The classes are open to an

Alona [7]

Answer:

A. 0.5

B. 0.32

C. 0.75

Step-by-step explanation:

There are

28 students in the Spanish class,
26 in the French class,
16 in the German class,
12 students that are in both Spanish and French,
4 that are in both Spanish and German,
6 that are in both French and German,
2 students taking all 3 classes.

So,

2 students taking all 3 classes,
6 - 2 = 4 students are in French and German, bu are not in Spanish,
4 - 2 = 2 students are in Spanish and German, but are not in French,
12 - 2 = 10 students are in Spanish and French but are not in German,
16 - 2 - 4 - 2 = 8 students are only in German,
26 - 2 - 4 - 10 = 10 students are only in French,
28 - 2 - 2 - 10 = 14 students are only in Spanish.

In total, there are

2 + 4 + 2 + 10 + 8 + 10 +14 = 50 students.

The classes are open to any of the 100 students in the school, so

100 - 50 = 50 students are not in any of the languages classes.

A. If a student is chosen randomly, the probability that he or she is not in any of the language classes is

$\dfrac{50}{100} =0.5$

B. If a student is chosen randomly, the probability that he or she is taking exactly one language class is

$\dfrac{8+10+14}{100}=0.32$

C. If 2 students are chosen randomly, the probability that both are not taking any language classes is

$0.5\cdot 0.5=0.25$

So, the probability that at least 1 is taking a language class is

$1-0.25=0.75$

3 0

3 years ago

Maksim231197 [3]

Answer:

D. x=1

Step-by-step explanation:

Image can be rewritten as 3x + 6 = 9.

Solve for x.

3x +6 = 9

Isolate x by subtracting 6 from both sides.

3x = 3

Get rid of the 3 by dividing by 3 on both sides.

x = 1

Hope this helped.

8 0

2 years ago

9. Tell whether the table is a linear equation and explain why

MaRussiya [10]

The table is linear because the change because it had a constant slope when we solve for change in y / change in x for each of the data points given. That slope is -0.5 and it’s constant.

7 0

3 years ago

What is the least common denominator of<br> 1/3 and 5/9

crimeas [40]

Answer:

Equivalent Fractions with the LCD

1/3 = 3/9

5/9 = 5/9

Solution:

Rewriting input as fractions if necessary:

1/3, 5/9

For the denominators (3, 9) the least common multiple (LCM) is 9.

LCM(3, 9)

Therefore, the least common denominator (LCD) is 9.

Calculations to rewrite the original inputs as equivalent fractions with the LCD:

1/3 = 1/3 × 3/3 = 3/9

5/9 = 5/9 × 1/1 = 5/9

4 0

3 years ago