Respuesta :

Answer:

y= -4

Step-by-step explanation:

x+y=42.   We know that x plus y equals 42.

x=2y .   We also know that x equals twice y.

2y+y=42.   Since we know that x=2y, we're going to replace x with 2y from the original equation, simplified would be 3y=42.

y=14.   3y=42 simplified is y=14, this is because we divided both sides by 3 (since 3 and 42 are both divisible by 3) (btw divisible by 3 simply means that it can be divided by 3)

x+14=42.   Now that we know what y equals, let's replace y with 14 from the original equation.

x=28.  Now that we know that x=28 and y=14, we know that y is always x/2.

When x=-8, we divide it by 2 and get, -4.

Not absolutely positive as this was all mental math, but hope this helps! :)

The value of the variable y at x = -8, will be negative 49.

What are ratio and proportion?

A ratio is a collection of ordered integers a and b represented as a/b, with b never equaling zero. A proportionate expression is one in which two items are equal.

The numbers x and y are inversely proportional. Then we have

y ∝ 1/x

y = k/x    ...1

When the sum of x and y is 42. Then the equation will be

x + y = 42   ...2

x is twice y. Then the equation will be

x = 2y   ...3

From equations 2 and 3, we have

2y + y = 42

3y = 42

y = 14

Then the value of x will be

x = 2(14)

x = 28

Then the value of k will be

14 = k / 28

k = 392

Then the equation will be

y = 392 / x

Then the value of the variable y at x = -8, will be

y = 392 / (-8)

y = -49

Thus, the value of the variable y at x = -8, will be negative 49.

More about the ratio and the proportion link is given below.

https://brainly.com/question/14335762

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