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
MrRa [10]
3 years ago
13

Ifx + 2y = 8 and - 2x + 3y = 5, then what is the value of 2x + 3y?

Mathematics
1 answer:
Charra [1.4K]3 years ago
4 0

Answer:

13

Step-by-step explanation:

Given the 2 equations

x + 2y = 8 → (1)

- 2x + 3y = 5 → (2)

Rearrange (1) expressing x in terms of y by subtracting 2y from both sides

x = 8 - 2y → (3)

Substitute x = 8 - 2y into (2)

- 2(8 - 2y) + 3y = 5 ← distribute and simplify left side

- 16 + 4y + 3y = 5

- 16 + 7y = 5 ( add 16 to both sides )

7y = 21 ( divide both sides by 7 )

y = 3

Substitute y = 3 in (3) for corresponding value of x

x = 8 - 2(3) = 8 - 6 = 2

Thus x = 2 and y = 3

2x + 3y = 2(2) + 3(3) = 4 + 9 = 13

You might be interested in
Can someone SMART redo these questions I mean I made a seven and I did all I could I need to know what went wrong
adoni [48]
2. 8x -28 = -140
8x -28 + 28 = -140 + 28
8x = -112
8x/8 = -112/8
x = -14

3. -9 + x/3 = -23
-9 + 9 + x/3 = -23 + 9
x/3 = -14
x/3/3 = -14/3
x = -14/3

4. x/-1.5 - 3.5 = -13.5
x/-1.5 - 3.5 + 3.5 = -13.5 + 3.5
x/1.5 = -10
x/-1.5/-1.5= -10/-1.5
x = 20/3

5.-6(x + 3) = -36
-6x - 18 = -36
-6x - 18 + 18 = -36 + 18
-6x = -18
-6x/-6 = -18/-6
x = 3

6. k + 3.7/9.8 = -0.22
k + 3.7/9.8/9.8 = -0.22/9.8
k + 3.7 = -2.156
k + 3.7 - 3.7 = -2.156 - 3.7
k = -5.856

7. 12(x - 6) = -108
12x - 72 = -108
12x - 72 + 72 = -108 + 72
12x = -36
12x/12 = -36/12
x = -3

8. -21.83x - -19.9 = -23.83
-21.83x + 19.9 = -23.83
-21.83x + 19.9 - 19.9 = -23.83 - 19.9
-21.83x = -43.73
-21.83x/-21.83 = -43.73/-21.83
x = 2

9. -10x - 68 + x = 40
-9x - 68 = 40
-9x -68 + 68 = 40 + 68
-9x = 108
-9x/-9 = 108/-9
x = -12

10. -34 - 3x - 2x = 71
-34 - 5x = 71
-34 + 34 - 5x = 71 + 34
-5x = 105
-5x/-5 = 105/-5
x = -21

11. 3x - 77 - 8x = 23
-5x - 77 = 23
-5x - 77 + 77 = 23 + 77
-5x = 100
-5x/-5 = 100/-5
x = -20

12. 3x - 5(2x - 12) = 123
3x - 10x + 60 = 123
-7x + 60 = 123
-7x + 60 - 60 = 123 - 60
-7x = 63
-7x/-7 = 63/-7
x = -9

13. -3x + 6(x + 6) = 15
-3x + 6x + 36 = 15
3x + 36 = 15
3x + 36 - 36 = 15 - 36
3x = -21
3x /3 = -21/3
x = -7

14. 5x + 2(4x - 9) = -174
5x + 8x - 18 = -174
13x - 18 = -174
13x - 18 + 18 = -174 + 18
13x = -156
13x/13 = -156/13
x = -12

15. -3x + 6(5x + 3) = -171
-3x + 30x + 18 = -171
27x + 18 = -171
27x + 18 - 18 = -171 - 18
27x = -189
27x/27 = -189/27
x = -7










5 0
3 years ago
What is the solution to the equation 1/4x +2= -5/8x - 5
nalin [4]

Answer:

x = -8

Step-by-step explanation:

1/4x +2= -5/8x - 5

Add 5/8x to each side

1/4x +5/8x +2= -5/8x+5/8x - 5

1/4x+5/8x +2=  - 5

Subtract 2 from each side

1/4x+5/8x +2-2=  - 5-2

1/4x+5/8x =  - 7

Get a common denominator

1/4 *2/2 x + 5/8x = -7

2/8x + 5/8x = -7

7/8x = -7

Multiply each side by 8/7

8/7x * 7/8x = -7 *8/7

x = -8

7 0
2 years ago
Read 2 more answers
What’s the answer to (-8x) + x + (-2x)
Tresset [83]

(-8x) + x + (-2x) = -8x + x - 2x = -9x

8 0
3 years ago
Read 2 more answers
Triangle ABC is similar to triangle DEF.
amid [387]

Answer:

1.5

Step-by-step explanation:

12 / 8 = 1.5

8 0
2 years ago
Plz help ASAP I will add branliest to the first answer, I need to solve for the letter
harkovskaia [24]

Answer:

6. r=2

8.x=3

Step-by-step explanation:

6. 4r-3=5

4r-3=5 add 3 to both sides

4r=8 divide 4 by both sides

r=2

8. 5x-6=9

5x-6=9 add 6 to both sides

5x=15 divide 5 by both sides

x=3

6 0
2 years ago
Read 2 more answers
Other questions:
  • <img src="https://tex.z-dn.net/?f=6.25%20%5Ctimes%201.4" id="TexFormula1" title="6.25 \times 1.4" alt="6.25 \times 1.4" align="a
    14·1 answer
  • Who want to date me im 13 name is deanna i love dua lipa
    8·1 answer
  • In a police on the interstate, the suspect's car reached a speed of 88 miles per hour for the total 15 minutes. In the time, how
    9·2 answers
  • What is 11/2 reduced? 11/2 is a fraction:)
    6·1 answer
  • Big trouble what is 99-30
    14·1 answer
  • WHAT IS THE GOAL FOR THE TOPIC OF FINDING THE CENTER AND THE RADIUS OF A CIRCLE GIVEN THE EQUATION?​
    5·1 answer
  • WILL GIVE BRAINLEST TO CORRECT ANSWER A researcher is dividing a sample with a mass of 9.2 x 10-3 grams into smaller samples wit
    6·1 answer
  • Find the 14th term of the geometric sequence 2,6,18, ...
    9·2 answers
  • Twice the sum of a number and 11 is 34.<br><br> What is the number?
    9·2 answers
  • WHICH ANGLE IS CONGRUENT TO AFB
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!