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3 years ago

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:

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

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one-third of the people from country A claim that they are from country B, and the rest admit they are from country A. One-fourt

In-s [12.5K]

Answer: 3 : 2

Step-by-step explanation:

Let A represents the total population of country A and B represents the total population of country B.

According to the question,

$\text{The population of country A that admit they are from B} = \frac{1}{3}\text{ of }A$

⇒ $\text{ The population of A that admit they are from country A }= A - \frac{1}{3} \text{ of } A$

$= \frac{3-1}{3} A$

$= \frac{2}{3} A$

$\text{The population of country B that admit they are from A} = \frac{1}{4}\text{ of }B$

⇒ $\text{ The total population that claims that they are from A }= \frac{2}{3} A +\frac{1}{4} B$

But, Again according to the question,

The total population that claims that they are from A = one half of the total population of A and B.

⇒ $\frac{2}{3} A + \frac{1}{4} B= \frac{1}{2}(A+B)$

⇒ $\frac{2}{3} A + \frac{1}{4} B= \frac{1}{2}A+\frac{1}{2}B$

⇒ $\frac{2}{3} A - \frac{1}{2}A= \frac{1}{2}B-\frac{1}{4} B$

⇒ $\frac{4}{6} A - \frac{3}{6}A= \frac{2}{4}B-\frac{1}{4} B$

⇒ $\frac{1}{6} A = \frac{1}{4} B$

⇒ $A =\frac{6}{4}B$

⇒ $\frac{A}{B} =\frac{3}{2}$

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2 years ago

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Answer:

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Step-by-step explanation:

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2 years ago

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