- Classify the quadrilateral in as many ways as possible. .

Mary has a collection of nickels and quarters for a total of $4.90. If she has 42 coins in total, how many of each kind are ther

damaskus [11]

Answer:

14 quarters and 28 nickels

Step-by-step explanation:

System of Equations where x = number of quarters and y = number of nickels

(1) equation with value of each coin

0.25(x)+0.05(y) = 4.90

(2) total number of coins

x + y = 42

Solve system of equations using either substitution or elimination

(elimination multiplying equation 2 by -0.5)

.25(x) + 0.05(y) = 4.90

-0.05(x) - 0.05(y) = 42 * (-0.05)

(3) Resulting equation

.20(x) = 2.8

x = 14

plug x into equation 2

14 + y = 42

y = 28

There are 14 quarters and 28 nickels in Mary's collection.

5 0

3 years ago

We have x = 7 so now solve for y by replacing x with 7 in this equation 2x + y = 20

Ivahew [28]

Answer:

y=6

Step-by-step explanation:

2(7)=14.

subtract both sides by 14.

y=6

7 0

3 years ago

Read 2 more answers

Which shows the expression below simplified? 0.00048 - (3.4 × 10-5) A. 4.46 × 10-4 B. 3.39952 × 10-5 C. 4.46 × 10-5 D. 1.4 × 10-

MakcuM [25]

Option C

The simplified form of given expression is $4.46 \times 10^{-4}$

Solution:

Given that we have to simplify the expression shown below

$0.00048 - (3.4 \times 10^{-5})$

Let us first convert 0.00048 to scientific notation

Steps to follow:

Move the decimal point in your number until there is only one non-zero digit to the left of the decimal point. The resulting decimal number is a.

Count how many places you moved the decimal point. This number is b.

If you moved the decimal to the left b is positive.

If you moved the decimal to the right b is negative.

If you did not need to move the decimal b = 0.

Write your scientific notation number as a x 10^b and read it as "a times 10 to the power of b."

Remove trailing 0's only if they were originally to the left of the decimal point.

$0.00048 = 4.8 \times 10^{-4}$

So the given expression becomes,

$\rightarrow 4.8 \times 10^{-4} - 3.4 \times 10^{-5}$

Let us make the exponent of second term as -4

$\rightarrow 4.8 \times 10^{-4} - 0.34 \times 10^{-4}$

Take $10^{-4}$ as common term,

$\rightarrow 10^{-4} (4.8 - 0.34)$

$\rightarrow 4.46 \times 10^{-4}$

Thus option C is correct

7 0

3 years ago

15 points ! precalc question with graph

Semmy [17]

x-intercepts are where the graph crosses the x-axis. These are (-1, 0) and (3, 0) from the graph.

y-intercepts are where the graph crosses the y-axis. This is (0, -3) from the graph.

6 0

4 years ago

Read 2 more answers

HELP ASAP solve the equation using the properties of equality. 89= -5d+9

sergey [27]

Answer:

d = -16

Step-by-step explanation:

Step 1: Write equation

89 = -5d + 9

Step 2: Solve for d

Subtract 9 on both sides: 80 = -5d

Divide both sides by -5: -16 = d

Step 3: Check

Plug in x to verify if it's a solution.

89 = -5(-16) + 9

89 = 80 + 9

89 = 89

8 0

3 years ago