1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
mrs_skeptik [129]
3 years ago
9

She has 40 coins all made up of quarters and dimes, And when she counted them up she had $7.75 from them, how much of each did s

he have?
Mathematics
1 answer:
Dmitry [639]3 years ago
6 0

Answer:

x = number of quarters = 25

y = number of dimes = 15

Step-by-step explanation:

Let

x = number of quarters

y = number of dimes

1 dime = $0.10

1 quarter = $0.25

x + y = 40 (1)

0.25x + 0.10y = 7.75 (2)

From (1)

x = 40 - y

Substitute x = 40 - y into (2)

0.25x + 0.10y = 7.75 (2)

0.25(40 - y) + 0.10y = 7.75

10 - 0.25y + 0.10y = 7.75

- 0.25y + 0.10y = 7.75 - 10

-0.15y = -2.25

y = -2.25/-0.15

y = 15

Substitute y = 15 into (1)

x + y = 40 (1)

x + 15 = 40

x = 40 - 15

x = 25

x = number of quarters = 25

y = number of dimes = 15

Total quarters = 25 × $0.25

= $6.25

Total dimes = 15 × $0.10

= $1.5

You might be interested in
If the unit selling price 2.50 and the unit cost 1.00 what action is needed to maintain Thr gross margin percentage when unit co
xxMikexx [17]
Raise the unit selling price .25 cents from $2.50 to $2.75
6 0
4 years ago
a cell phone battery uses 1/3 of its charge in 3/8 of a day. How much charge will it use in one day?​
brilliants [131]

\bf \begin{array}{ccll}charge&day\\\cline{1-2}\frac{1}{3}&\frac{3}{8}\\\\x&1\end{array}\implies \cfrac{~~\frac{1}{3}~~}{x}=\cfrac{~~\frac{3}{8}~~}{1}\implies \cfrac{~~\frac{1}{3}~~}{\frac{x}{1}}=\cfrac{3}{8}\implies \cfrac{1}{3}\cdot \cfrac{1}{x}=\cfrac{3}{8}\\\\\\\cfrac{1}{3x}=\cfrac{3}{8}\implies 8=9x\implies \cfrac{8}{9}=x

3 0
4 years ago
Dan earns a commission of 15% on his sales. Last month his sales were: $550.23, $793.23,
elixir [45]

9514 1404 393

Answer:

  $533.86

Step-by-step explanation:

The sum of the sales amounts is $3,559.07. Dan's commission is ...

  0.15 × $3,559.07 = $533.86

5 0
3 years ago
Which of the following is the solution to the following systems of inequalities? (picture included)
Ymorist [56]

Answer:

  C.  (see the attachment)

Step-by-step explanation:

Both inequalities include the "or equal to" case, so both boundary lines will be solid. That excludes choices A and D.

The first inequality is plotted the same way in all graphs, so we must look at the second inequality. The relationship of y and the comparison symbol is ...

  -y ≥ (something)

If we multiply by -1, we get ...

  y ≤ (something else)

This means the solution space will be <em>on or below (less than or equal to) the boundary line</em>. This is the shaded area in graph C. (Graph B shows shading <em>above</em> the line.)

___

<em>Further comment</em>

Since the boundary for the second inequality is fairly steep, "above" and "below" the line can be difficult to see. Rather, you can consider the relationship of x to the comparison symbol. For the second inequality, that is ...

  x ≥ (something)

indicating the solution space is <em>on or to the right of the boundary line</em>.

3 0
3 years ago
How do you solve this?
goldfiish [28.3K]
20×(1.4)^(6−1) =107.5648
3 0
3 years ago
Other questions:
  • Can someone help me please solving these maths problems thanks.
    15·2 answers
  • Solve 3[–x + (2 x + 1)] = x – 1. <br><br> X= ?
    9·2 answers
  • The bus you take every morning always arrives anywhere from 2 minutes early to 15 minutes late and it is equally likely that it
    7·1 answer
  • A rectangular prism has a length of 9 cm, a width of 5 cm, and its volume is 180 cubic centimeters. What is the height of the pr
    10·2 answers
  • Which expression is equivalent to -6(6 + 8) + 4
    10·2 answers
  • Find the value of X<br> (5x+4)°+(8x-71)°
    6·1 answer
  • Find the area and perimeter of trapezoid ABCD. round your answers to the nearest tenth.
    9·1 answer
  • What factors go into 24
    9·2 answers
  • What is the square root of 1 over 49?
    12·2 answers
  • Hi guys can y’all help me with this problem? i’m stuck :p
    10·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!