Solve following system of equations using the elimination method and enter the value of x.

Use an algebraic approach to solve the problem.

qaws [65]

Answer:

Her first exam score was a 78, her second exam score was a 89, and his third exam score was a 94.

Step-by-step explanation:

Use the formula for the mean: sum of elements / number of elements

Let x represent her first exam score.

Her second exam score can be represented by x + 11, since it was 11 points better than her first.

Her third exam score can be represented by (x + 11) + 5, since it was 5 points better than her second.

Plug in all of these expressions into the mean formula. Plug in 87 as the mean, and plug in 3 as the number of elements (since there are 3 scores):

mean = sum of elements / number of elements

87 = ( (x) + (x + 11) + (x + 11) + 5 ) / 3

Add like terms and solve for x:

87 = (3x + 27) / 3

261 = 3x + 27

234 = 3x

78 = x

So, her first score was a 78.

Find her second score by adding 11 to this:

78 + 11 = 89

Find her third score by adding 5 to the second score:

89 + 5 = 94

Her first exam score was a 78, her second exam score was a 89, and his third exam score was a 94.

6 0

3 years ago

Danielle earns a 8.25% commission on everything she sells at the electronics store where she works. She also earns a base salary

Mariulka [41]

Answer: her sales last week was $4300.

Step-by-step explanation:

Let x represent her her sales in a week.

Danielle earns a 8.25% commission on everything she sells at the electronics store where she works. This means that the commission she gets if she makes sales of $x is 0.0825x

She also earns a base salary of $675 per week. The expression for the total earnings for a week in which she made sales of $x would be

0.0825x + 675

if her total earnings for last week were $1,029.75, it means that

0.0825x + 675 = 1029.75

0.0825x = 1029.75 - 675

0.0825x = 354.75

x = 354.75/0.0825

x = $4300

3 0

3 years ago

A cone has a radius of 4 units and a height of 6 units.

Usimov [2.4K]

We know, Volume of a Cylinder = πr² h/3
v = 3.14 * 4² * 6/3
v = 3.14 * 16 * 2
v = 100.48

In short, Your Answer would be Option B

Hope this helps!

7 0

3 years ago

Read 2 more answers

A bean plant grows at a constant rate for a month. After 10 days, the plant is 25 centimeters tall. After 20 days, the plant is

wariber [46]

Y = 2x + 5

If you take the height at 10 days, 25 centimeters, after 10 more days the height is 45 centimeters, meaning for those 10 extra days the been plant grown 20 centimeters. Since we're told the plant is growing at a constant rate, this shows the bean plant is growing 2 centimeters per day. We can represent this with y = 2x. (After 10 days, the bean plant will be 20 centimeters, after 20 days, the bean plant will be 40 centimeters, etc.)

However, this is not completely true yet. As you can see, after the first 10 days the plant is not 20 centimeter, it's 25 centimeters. We already know the rate in which the plant is changing, but now we need to find the height that the plant was originally, before it started growing.

After the first 10 days, the plant is 25 centimeters tall. Since we know that the plant is growing 2 centimeters per day, we can subtract 20 from 25 to find the original height of the bean plant.

25 - 20 = 5
The bean plant was originally 5 centimeters.

This makes our final equation y = 2x + 5.
2x is the slope, and 5 is the y intercept.

Hope this helps1!

5 0

3 years ago

Which expression is equivalent to this expression? x(2x + 3) A) 2x2 + 3 B) 2x2 + 3x C) 2x2 - 3x Eliminate D) 3x + 3

ira [324]

Answer:

B

Step-by-step explanation:

x(2x + 3)

Expand the brackets.

x(2x)+x(3)

Multiply the terms.

2x² + 3x

The answer is 2x² + 3x.

3 0

3 years ago

Read 2 more answers