All categories

3 years ago

SoIve the system of equations by elimination. (Addition) 1)-2x + 4y = -22 2x + 8y = –26

Mathematics

2 answers:

Morgarella [4.7K]3 years ago

8 0

Answer:

(3, - 4 )

Step-by-step explanation:

Given the 2 equations

- 2x + 4y = - 22 → (1)

2x + 8y = - 26 → (2)

Adding the 2 equations term by term will eliminate the x- term, that is

12y = - 48 ( divide both sides by 12 )

y = - 4

Substitute y = - 4 into either of the 2 equations and solve for x

Substituting into (2)

2x + 8(- 4) = - 26

2x - 32 = - 26 ( add 32 to both sides )

2x = 6 ( divide both sides by 2 )

x = 3

solution is (3, - 4 )

Rufina [12.5K]3 years ago

6 0

Answee:

We have these two equations:

-2x +4y =-22

2x + 8y -26

We need to try to get the same number multiplying both x or y, I think we can make the 2 of the first equation negative, for that, we multiply all the equation by -1:

2x + 8y =-26 ---- -2x - 8y =26

Now we have this:

-2x +4y = -22

-2x -8y = 26

Now e substract both equations:

-2x - (-2x) +4y -(-8y) = -22-26

12y = -48

Y = -48/12 = -4

And we replace to get x

-2x + 4y = -22

-2x +4*(-4)=-22

-2x - 16 = -22

x= -6/-2 =3

You might be interested in

Which expressions are equivalent to 3(4h + 2k)?

faltersainse [42]

Answer:

Step-by-step explanation:

If we distribute the 3 to the equation in the parenthesis, we end up with this

12h + 6k

Now, let's do the same thing for the other two equations

3(2k + 4h) = 6k + 12h

You can rearrange this equation to look like 12h+ 6k, making it the exact same as 3(4h + 2k).

So A is equivalent

How about B?

3(4h + 2h) = 12h + 6h = 18h

18h does not equal 12h + 6k, so B is not equivalent

5 0

3 years ago

4) The path of a satellite orbiting the earth causes it to pass directly over two

Naily [24]

Answers:

Satellite is approximately <u>2446.43 km</u> from station A.
Satellite is approximately <u>2441.61 km</u> above the ground.

=========================================================

Explanation:

I'm assuming tracking stations A and B are at the same elevation and are on flat ground. In reality, this is likely not the case; however, for the sake of simplicity, we'll assume this is the case.

The diagram is shown below. Points A and B describe the two stations, while point C is the satellite's location. Point D is on the ground directly below the satellite. We have these lengths

AB = 60 km
AD = x
CD = h

Focusing on triangle ACD, we can apply the tangent rule to isolate h.

tan(angle) = opposite/adjacent

tan(A) = CD/AD

tan(86.4) = h/x

x*tan(86.4) = h

h = x*tan(86.4)

We'll use this later in the substitution below.

--------------------

Now move onto triangle BCD. For the reference angle B = 85, we can use the tangent rule to say

tan(angle) = opposite/adjacent

tan(B) = CD/DB

tan(B) = CD/(DA+AB)

tan(85) = h/(x+60)

tan(85)*(x+60) = h

tan(85)*(x+60) = x*tan(86.4) ............. apply substitution; isolate x

x*tan(85)+60*tan(85) = x*tan(86.4)

60*tan(85) = x*tan(86.4)-x*tan(85)

60*tan(85) = x*(tan(86.4)-tan(85))

x*(tan(86.4)-tan(85)) = 60*tan(85)

x = 60*tan(85)/(tan(86.4)-tan(85))

x = 153.612786190499

--------------------

We'll use this approximate x value to find h

h = x*tan(86.4)

h = 153.612786190499*tan(86.4)

h = 2441.60531869599

h = 2441.61 km is how high the satellite is above the ground.

Return to triangle ACD. We'll use the cosine rule to determine the length of the hypotenuse AC

cos(angle) = adjacent/hypotenuse

cos(A) = AD/AC

cos(86.4) = x/AC

cos(86.4) = 153.612786190499/AC

AC*cos(86.4) = 153.612786190499

AC = 153.612786190499/cos(86.4)

AC = 2446.43279498247

AC = 2446.43 km is the distance from the satellite to station A.

6 0

3 years ago

By road, without any stopovers, it would take Saad 14 hours and 27 minutes to reach Islamabad from Karachi. He leaves Karachi at

Furkat [3]

Answer:

8:48 p.m.

Step-by-step explanation:

First order half an hour plus 19 minutes used to refuel you will get 49 minutes then add it to the 14 hours 27 minutes you get dinner was 16 minutes then added to the time when he leaves Karachi which is 5:34 am which you get 8:48 p.m.

4 0

3 years ago

PLEASE HELP <br> WILL GIVE BRAINLIEST AND 5.0 RATING

jasenka [17]

Answer:

Step-by-step explanation:

(-4,-5)

move up 3 units

change in y-axis

-5+3=-2

(-4,-2)

4 0

3 years ago

the initial cost to set up a website is $48. it cost $44 per month to maintain the website . how many months will you be able to

Delicious77 [7]

We would start with 400 - 48, to cover the initial cost. We would be left with 352 dollars to spare for the monthly bill. 352 divided by 44, which is the monthly cost, would be 8. The website could be set up and held for 8 or 9 months, depending on if the initial cost is paid at the same time or before the first monthly one.

8 0

3 years ago

Read 2 more answers