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3 years ago

Please provide steps. I have a test soon.

Mathematics

1 answer:

marishachu [46]3 years ago

6 0

Answer:

B) 5x+15y=30

5x-5y=10

Step-by-step explanation:

First, we solve the top equations by addition. Multiply the first one by -4.

-4x-12y=-24

4x-8y=4

This equals -20y=-20, so y=1. Now we put that back into either equation and find that x=3. So the solution set is (3,1)

Plugging those into each of the possible choices, we find that the answer is

B) 5x+15y=30. 5(3)+15(1)=30 15+15=30. 30=30 CHECK

5x-5y=10 5(3)-5(1)=10. 15-5=10. 10=10. CHECK

You might be interested in

Part A). Emily participates in a trivia quiz show. In each round, 20 points are awarded for a correct answer and 10 points are d

rosijanka [135]

Answer

A. -30 points

B. 60 points

Step-by-step explanation:

20 points for correct answer and 10 points deducted for wrong answer

Each deduction is -10 while each correct answer gives + 20

4 questions correctly and 11 incorrectly

= 4(20) + 11(-10)

= 80-110 = -30 points

Second round

7 correct, 8 incorrect

= 7(20) - 8(10)

= 140-80 = 60 points

4 0

3 years ago

HELP PLEASE.<br> Both questions.

egoroff_w [7]

The slope definitions:

The slope is the change in y divided by the change in x.

The slope is the ratio of rise to run.

The slope is the rate of change of the function at a certain point.

The slope is the first derivative of a function.

The slope is the tangent of the slant/inclined angle

So we are interested in this one: "The slope is the ratio of rise to run"

Logically, the gas in the tank decreases as the distance traveled increases.

So they are inversely proportional.

Let's look at the scale of the axis now///

After examine, as we travel 20 miles, our gas in the tank decrease by 3 gallons...i.e. 3 gallons have been consumed to move this distance

I hope that helps!

I am with you if you faced any difficulties!

5 0

4 years ago

If the endpoints of the diameter of a circle are (−8, −6) and (−4, −14), what is the standard form equation of the circle?

kondaur [170]

Equation of the circle is $(x+6)^{2}+(y+10)^{2}=20$ .

Solution:

The endpoints of the diameter of a circle are (–8, –6) and (–4, –14).

Center of the circle = Mid point of the diameter

Mid point formula:

$$P(x, y)=\left(\frac{x_{1}+x_{2}}{2}, \frac{y_{1}+y_{2}}{2}\right)$

Here, $x_1=-8, y_1=-6, x_2=-4, y_2=-14$

$$P(x, y) =\left(\frac{-8-4}{2}, \frac{-6-14}{2}\right)$

$$P(x, y) =\left(\frac{-12}{2}, \frac{-20}{2}\right)$

$$P(x, y) =(-6, -10)$

Center of the circle = (–6, –10)

Radius is the distance between center and any endpoint of the diameter.

To calculate the radius using distance formula.

$r=\sqrt{\left(x_{2}-x_{1}\right)^{2}+\left(y_{2}-y_{1}\right)^{2}}$

Here, $x_1=-6, y_1=-10, x_2=-8, y_2=-6$

$r=\sqrt{\left(-8-(-6)\right)^{2}+\left(-6-(-10)}\right)^{2}}$

$r=\sqrt{(-8+6)^{2}+(-6+10)^{2}}$

$r=\sqrt{(-2)^{2}+(4)^{2}}$

$r=\sqrt{20}$ units

The standard form of the equation of a circle is

$(x-a)^{2}+(y-b)^{2}=r^{2}$ , where (a, b) are center and r is the radius.

Here, center = (–6, –10) and $r=\sqrt{20}$

$(x-(-6))^{2}+(y-(-10))^{2}={(\sqrt{20})} ^{2}$

$(x+6)^{2}+(y+10)^{2}=20$

Equation of the circle is $(x+6)^{2}+(y+10)^{2}=20$ .

4 0

3 years ago

Tv originally cost $400 if the price of the TV increase by 15% what is the new price

Verizon [17]

Answer:

$460

Step-by-step explanation:

Thus, a product that normally costs $400 with a 15 percent discount will cost you $340.00, and you saved $60.00. You can also calculate how much you save by simply moving the period in 15.00 percent two spaces to the left, and then multiply the result by $400 as follows: $400 x .15 = $60.00 savings.

3 0

3 years ago

Write an equation and solve each problem. The ages of three brothers are consecutive integers with the sum of 96. How old are th

Alexxx [7]

Hi,

Let the

Youngest brothers age = x+2

Middle brothers age = x+4

Oldest brothers age = x+6

So,

Youngest brothers age = x+2 = 28+2 = 30 years of age

Middle brothers age = x+4 = 28+4 = 32 years of age

Oldest brothers age = x+6 = 28+6 = 34 years of age

Have a great day!

4 0

3 years ago