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
Schach [20]
3 years ago
10

System of equations ( substitution methods) can someone solve these problems x=3y-5 ; x+y=3 y=x ; 3x+3y=18 y=3x+4 ; 5x-y=0

Mathematics
1 answer:
Tcecarenko [31]3 years ago
7 0

Answer:

(1,2)

(3,3)

(-1/2, 11/2)

Step-by-step explanation:

A system of equations is 2 or more equations for which the same x,y solution exists. We can solve the system in three ways: elimination, substitution, or graphing. Substitution can be used by substituting the value of one variable into the equation.

<u>Pair x=3y-5 and x+y=3</u>

Because x=3y-5, we can substitute 3y-5 into x in x+y=3

x+y=3

(3y-5)+y=3

3y-5+y=3

4y-5=3

4y-5+5=3+5

4y=8

y=2

We now substitute y=2 into x=3y-5.

x=3y-5

x=3(2)-5

x=6-5

x=1

<u>Pair y=x and 3x+3y=18</u>

Because y=x, we can substitute x into y in 3x+3y=18

3x+3y=18

3x+3x=18

6x=18

x=3

We now substitute x=3 into y=x.

y=3.

<u>Pair y=-3x+4 and 5x-y=0</u>

Because y=-3x+4, we can substitute -3x+4 into y in 5x-y=0

5x-y=0

5x-(-3x+4)=0

5x+3x+4=0

8x+4=0

8x=-4

x=-1/2

We now substitute x=-1/2 into y=-3x+4

y=-3x+4

y=-3(-1/2)+4

y=3/2+4

y=11/2

You might be interested in
A store makes a $0.45 profit on every toy they sell. If they made $237.15 in profit last month, how many toys did they sell?
iren2701 [21]

Answer:

527

Step-by-step explanation:

237.15/0.45 = 527

6 0
3 years ago
Read 2 more answers
Please help look at the picture
k0ka [10]

Answer:

y = - 5x - 1

Step-by-step explanation:

The first thing to do (always) is pay attention to x =0. That at least gives you a partial answer. y = y' - 1. when you put 0 in for whatever y' is you get 0. What about the other numbers? How did they come about.

We have another clue. Whenever you put in a positive number for x, you get a negative answer for y. That's interesting. So y' has a minus sign associated with it.

y = -ax - 1    Make a>0 so there is only 1 minus sign. x cannot have an even power, because an even power would make everything positive except the -1.  

So we'll start with y= - ax - 1 We'll also make the assumption that a = 1

y = - x - 1 That won't work. a >1 otherwise x = 2 won't give - 11

y = -ax - 1

let x = 2

let y = - 11 Solve for a

y = - ax - 1

- 11 = -a*-2 - 1       add   1  to both sides

-11 + 1 = - a(-2) - 1 + 1

- 10 = -2a             Divide by - 2

- 10/-2 = -2a/-2

a = 5

Answer: y = - 5x - 1

8 0
3 years ago
Miles bought a car that cost $23,556.to the nearest ten thousand,how much did the car cost
laila [671]
$20,000
In word form. he has twenty three thousand five hundred and fifty six, so we look to the digit next to the thousands, 3, and since its below 5, we keep 2 the same.
3 0
3 years ago
Without using calculator or table find the value of sin 15°​
lubasha [3.4K]

Answer:

.25881

Step-by-step explanation:

sin15

=sin(45-30)

=sin45.cos30-cos45.sin30

=(0.707×0.86)-(0.707×0.5)

=(0.6082)-(0.3535)

=0.25

6 0
3 years ago
A senior class at Smith High School has 84 students.
sattari [20]

Answer: 44 boys and 40 girls

Step-by-step explanation:

x = number of girls

x + 4 = number of boys

x + x + 4 = 84

2x + 4 = 84

2x = 80

x = 40

84 - 40 = 44

3 0
3 years ago
Other questions:
  • Is 2/3 bigger than 1/6
    15·2 answers
  • 9. A map of Texas has a scale of 1 in: 65 mi. The
    6·1 answer
  • Triangle abc is congruent to triangle xyz. angle a measures 50 degrees angle b measure 2 x plus 40 degrees and angle z measures
    12·1 answer
  • Dan had 175 dollars to spend on 6 books. After
    10·1 answer
  • GIVING BRAINLIEST! I have a plagiarism checker-
    7·1 answer
  • Slove it work it out
    9·1 answer
  • Simplify (i^24)^<img src="https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B2%7D" id="TexFormula1" title="\frac{1}{2}" alt="\frac{1}{2}"
    5·1 answer
  • HELP ASAP PLZ<br> find the perimeter of the figures shown below.
    8·2 answers
  • If Kaylee can type 408 words in 4 minutes, <br> how many words can she type in 24 minutes?
    15·2 answers
  • Can someone please give me the awnsers !!!!!!
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!