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
Jet001 [13]
2 years ago
8

I need help with all 3 please

Mathematics
1 answer:
olganol [36]2 years ago
6 0

Step-by-step explanation:

x +2y = 9. .....(1)

x - 2y = 5. .....(2)

from eqn (1)

x + 2y = 9

x = 9 - 2y.

substitute x = 9 - 2y into eqn (2)

9 - 2y - 2y = 5

-4y = 5 - 9

-4y = -4

y = 1

sub y = 1 into eqn (1)

x + 2y = 9

x + 2(1) = 9

x + 2 = 9

x = 9 - 2

x = 7.

(2) x + y = 9 ....(1)

x - 2y = 0 .....(2)

from eqn (2)

x - 2y = 0

x =0 + 2y

substitute x = 2y into eqn (1)

x + y = 9

(2y) + y = 9

3y = 9

y = 3

substitute y = 3 into eqn (2)

x - 2y = 0

x - 2(3) = 0

x - 6 = 0

x = 6.

(3) 2x + 7y = 5. ....(1)

2x + 3y = 9. .....(2)

from eqn (1)

2x + 7y = 5

7y = 5 - 2x

y = (5 - 2x)/7

sub y = (5 - 2x)/7 into eqn (2)

2x + 3y = 9

2x + 3(5 - 2x)/7 = 9

2x + (15 - 6x)/7 = 9

multiply through by 7

14x + 15 - 6x = 63

14x - 6x = 63 - 15

8x = 48

x = 6

sub x = 6 into eqn (1)

2x + 7y = 5

2(6) + 7y = 5

12 + 7y = 5

7y = 5 - 12

7y = -7

y = -1

You might be interested in
70% or 21/25 witch is greter
dlinn [17]

Answer:

21/25 Is greater!

Step-by-step explanation:

21/25 = 0.84 = 84% > 70%

8 0
3 years ago
Read 2 more answers
Please help with math homework show work<br><br>All of the questions
vagabundo [1.1K]
At least do number 3 so I can help with the rest. That ok with you?

3 0
2 years ago
Can sum1 answer these from least to created I need help?
PtichkaEL [24]

Answer:

for Earth it is 2.16 mm and Venus is 100.9 mm Pluto it is 250. millimeters make me it is 5.6 mm Mars it is 2.9 mm Sun it is 6.10 MM Jupiter it is a 70.10 MM of Saturn it is 25.8 MM Uranus it is 15.6 mm It Is 96.9 mm

3 0
3 years ago
sharon drops a rubber ball from a height of 160 feet every bounce sends the ball half as high as it was before what is the total
Elanso [62]

Answer:

10 feet.

Step-by-step explanation:

First time: 160/2=80.

Second time: 80/2=40.

Third time: 40/2=20.

Fourth time: 20/2=10.

Boom.

5 0
2 years ago
There are 8 performers who will present their comedy acts this weekend at a comedy club. One of the performers insists on being
Korvikt [17]
This is a permutations problem. There are only 7 comics you can move into different time slots, the 8th one being fixed in that last position. So you can look at it this way:
For the 1st position, you can choose from all 7 people. Once you've picked that one, you have 6 people to choose from for the 2nd position, and similarly for the remaining ones . This gives you 7x6x5x4x3x2x1 = 5040 ways to arrange them. And the last comic stays in the same position all the time so does not change this number. Make sense? If you need to demonstrate it to yourself, use a smaller number of comics, like 3 or 4, and write out the combinations to see that it works.
7 0
3 years ago
Other questions:
  • What is the area of this triangle?
    8·1 answer
  • Which of the following does not represent a function?
    6·1 answer
  • Choose the property of real numbers that justifies the equation.
    15·1 answer
  • 107/13 as a mixed number
    13·2 answers
  • A private club was reduced by 27 members in 3 weeks. Its size changed by the same number of members each week. What was the chan
    8·1 answer
  • What’s the missing term ?
    7·2 answers
  • Keith plans on eating 1 1/4 cups of tuna per day for 5 days. how much tuna does he need? is 4 cans enough?
    5·1 answer
  • HELP PLSSSSSSSSSSSSS DUE TODAY Complete each sentence with the correct expression from the box.Its spanish not math my bad
    10·1 answer
  • If T is the centroid of ∡MNP, TN = 16, MQ = 23, and RP = 18, find each missing measure.
    15·1 answer
  • B=3 V/h<br> I’m supposed to solve the question for V.
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!