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
dem82 [27]
3 years ago
9

X-5y-z=-20-2x-y-6z=25-x-4y-z=-15Solve by elimination

Mathematics
1 answer:
Tju [1.3M]3 years ago
6 0

Answer:

x = 0

y = 5

z = -5.

Step-by-step explanation:

X-5y-z=-20

-2x-y-6z=25

-x-4y-z=-15

Add equation 1 and 3:

-9y - 2z = -35 .......... A

Multiply the first equation by 2:

2x - 10y - 2z = -40

Now add this to equation 2:

-11y -8z = -15.............B

Now multiply equation A by -4:

36y + 8x = 140.........C

Add equations B and C:

25y = 125

y = 5.

Substitute for y in equation A:

-9*5 - 2z = -35

2z = -45 + 35 = - 10

z = -5.

Now find x by substituting for y and z in the first equation:

x - 5(5) - (-5) = -20

x - 20 = -20

x = 0.

You might be interested in
David wants to hang a mirror in his room. The mirror and frame must have an area of 8 square feet. The mirror is 2 feet wide and
andreyandreev [35.5K]
Represent the thickness of the frame by x. Framing the mirror will increase both its length and width by 2x. The area of the mirror with the frame is the product of the length and width which can mathematically be expressed as,
                                 
                                                A = (3 + 2x)(2 +2x) = 8

The equation above can be simplified into 4x^2 + 10x -2 = 0. This equation can still be further simplified by dividing it by 2. However, it will give an answer which is not found on the choices. Thus, the answer is the third choice. 
5 0
3 years ago
A number times 45 decreased by 12 is no more than 117​
Kay [80]

Answer: n*4512 is less than or equal to 117

Step-by-step explanation: n=number N*45=X X=Number more than 117. X decreased by 12 is less than or equal to 117.

5 0
3 years ago
What is organic fertilizer?​
chubhunter [2.5K]

Answer:

Organic fertilizer are fertilizers derived or gotten from animal matter, animal excrete, human excrete and vegetable matter. E.g- compost and crop residues. Natural occurring fertilizer include

Step-by-step explanation:animal waste from meat processing ,manure, slurry etc.

3 0
3 years ago
In the country of United States of Heightlandia, the height measurements of ten-year-old children are approximately normally dis
aliya0001 [1]

(A)

P(<em>X</em> < 61.25) = P((<em>X</em> - 55.4)/4.1 < (61.25 - 55.4)/4.1)

… ≈ P(<em>Z</em> ≤ 0.1427)

… ≈ 0.5567

(B)

P(<em>X</em> > 46.5) = P((<em>X</em> - 55.4)/4.1 > (46.5 - 55.4)/4.1)

… ≈ P(<em>Z</em> > -2.1707)

… ≈ 1 - P(<em>Z</em> ≤ -2.1707)

… ≈ 0.9850

5 0
3 years ago
Find the area of the triangle
kupik [55]
Area = 1/2 * base * height 
 = 1/2 * 20 * 6
 = 1/2 * 120
 = 60 ft^2
6 0
3 years ago
Other questions:
  • The ________ is a basic syst?me international (metric system) unit of mass.
    7·1 answer
  • Find two numbers whose sum is 58 and whose difference is 16 <br> Can anyone help me out
    11·1 answer
  • HELP IM ABT TO FAIL :)
    8·1 answer
  • Please help which ones are they? It’s graded and I don’t wanna fail...
    7·1 answer
  • Which of the following are trigonometric identities ? Check all that apply. Tan^2 x -
    15·1 answer
  • a person is scheduled to pick up 9 crates each crate weighs 1/4 how much weight will the delivery have
    9·2 answers
  • Plzzzz brainlest I swear
    12·2 answers
  • What is the radius of this circle?
    12·2 answers
  • You average weekly pay for the past six weeks is $140. What do you need to earn on the seventh week for the average to be $145?​
    9·1 answer
  • What is the distance from (-5,4) to (3,-2) ​
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!